Michael Bloomberg, the billionaire former mayor of New York City who announced on Monday that he will not mount a third-party run for president, scorched Republican candidates Donald Trump and Ted Cruz in an editorial.
Bloomberg was openly considering an independent run as part of a bid to stop Trump on the Republican side and Sen. Bernie Sanders on the Democratic side.
But in his Monday announcement, Bloomberg said that his candidacy could inadvertently help elect Trump or Cruz, the senator from Texas, both of whom he said were unpalatable options.
"As the race stands now, with Republicans in charge of both Houses, there is a good chance that my candidacy could lead to the election of Donald Trump or Senator Ted Cruz," Bloomberg wrote. "That is not a risk I can take in good conscience."
RELATED: Michael Bloomberg through the years
Michael Bloomberg through the years
Michael Bloomberg scorches Donald Trump and Ted Cruz in explaining why he won't run
Former New York Mayor Michael Bloomberg speaks during the C40 cities awards ceremony, in Paris, Thursday, Dec. 3, 2015. The C40 cities awards recognize cities for their leadership in tackling climate change across key sectors. (AP Photo/Thibault Camus)
344913 02: Bloomberg L.P. founder and CEO Michael Bloomberg poses for a portrait November 2, 1998 in the training room at his offices in New York City. (Photo by Chris Casaburi/Getty Images)
UNITED STATES - CIRCA 2000: Republican mayoral candidate Michael Bloomberg samples a slice of life at Francesco's Pizzeria on Third Ave. in Bay Ridge, Brooklyn. (Photo by Linda Rosier/NY Daily News Archive via Getty Images)
UNITED STATES - CIRCA 2000: Republican mayoral candidate Michael Bloomberg talks to passersby while campaigning at Broadway and W. 225th St. (Photo by David Handschuh/NY Daily News Archive via Getty Images)
UNITED STATES - CIRCA 2001: Republican mayoral candidate Michael Bloomberg exchanges high-fives with 7-year-old Matthew DePoalo while campaigning on Ditmars Blvd. in Astoria. (Photo by Andrew Savulich/NY Daily News Archive via Getty Images)
388464 18: Michael Bloomberg of Bloomberg News Service hosts a party before attending the annual White House Correspondents Dinner, April 28, 2001 in Washington DC. (Photo by Mark Wilson/Newsmakers)
NEW YORK, UNITED STATES: Michael Bloomberg, Republican candidate for New York mayor, speaks to the press in Brooklyn, New York, 26 September 2001. Bloomberg handsomely won the 25 September New York mayoral primary election to be the official Republican party candidate to replace New York Mayor Rudy Giuliani on January 1 next year, according to exit polls. AFP PHOTO Doug KANTER (Photo credit should read DOUG KANTER/AFP/Getty Images)
UNITED STATES - OCTOBER 26: Republican mayoral candidate Michael Bloomberg meets with the Daily News editorial board. (Photo by Pat Carroll/NY Daily News Archive via Getty Images)
Mayoral candidate Michael Bloomberg leaves the polling booth at PS 6 in Manhattan, NY. (Photo by Jennifer S. Altman/WireImage)
399131 02: Michael Bloomberg, the108th Mayor of the City of New York, gives his inaugural address January 1, 2002 at City Hall in New York City. (Photo by Getty Images)
UNITED STATES - CIRCA 2002: Mayor Michael Bloomberg chats with diners at the International House of Pancakes at 135th St. and Adam Clayton Powell Blvd. in Harlem, where he picked up the endorsement of the Rev. Calvin Butts. (Photo by Craig Warga/NY Daily News Archive via Getty Images)
NEW YORK, UNITED STATES: New York City Mayor Michael Bloomberg (C), and former New York Stock Exchange President William Johnston (R) listens to New York Stock Exchange Chairman Richard Grasso (R) on the bell podium before Bloomberg rang the opening bell to begin trading 02 January, 2002. AFP PHOTO Henny Ray ABRAMS (Photo credit should read HENNY RAY ABRAMS/AFP/Getty Images)
399944 03: New York Mayor Michael Bloomberg speaks at the swearing in of over 300 probationary firefighters January 22, 2002 at the Fire Academy on Randalls Island in New York City. The new class is the second to enter the academy since the World Trade Center attack, when the department lost 343 firefighters. The probationary firefighters will begin physical training and classroom instruction before being sent out to firehouses around the city., (Photo by Spencer Platt/Getty Images)
UNITED STATES - JANUARY 30: Mayor Michael Bloomberg makes his first State of the City address in the City Council chamber at City Hall. (Photo by Linda Rosier/NY Daily News Archive via Getty Images)
Mayor Michael Bloomberg cuts the ribbon to begin the opening of fall's Fashion Week in Bryant Park in Manhattan, NY. (Photo by Jennifer S. Altman/WireImage)
UNITED STATES - FEBRUARY 09: Mayor Michael Bloomberg stands amidst fire officials during funeral of Fire Lt. Kevin Pfeifer at St. Margaret's Church in Middle Village, Queens. Pfeifer, 42, who worked with Engine Co. 33 in lower Manhattan, was killed in the Sept. 11 terrorist attack on the World Trade Center. Bloomberg, attending his first firefighter funeral since taking office last month, eulogized the fallen hero and praised the bravery of all the firefighters who responded to the attacks. (Photo by Mike Albans/NY Daily News Archive via Getty Images)
401921 01: New York City Mayor Michael Bloomberg speaks at the unveiling of a fifty-foot high stainless steel tree by artist Roxy Paine March 5, 2002 in New York City's Central Park. The tree is one of five public artworks on display in Central Park sponsored by the Whitney Museum of American Art. (Photo by Mario Tama/Getty Images)
NEW YORK, UNITED STATES: New York Mayor Michael Bloomberg(L) and Attorney General John Ashcroft (R) look at memorial banners and posters in front of St. Paul's Chapel 09 April 2002 in New York City, before visiting ground zero at the site of the World Trade Center attacks. AFP PHOTO/POOL/Kathy WILLENS (Photo credit should read KATHY WILLENS/AFP/Getty Images)
403191 02: New York City Mayor Michael Bloomberg (C) and Fire Commissioner Nicholas Scoppetta (R) look on as a U.S. flag that once flew over Ground Zero is raised during a ceremony at City Hall Plaza April 1, 2002 in New York City. The flag was immortalized in a photograph by Thomas Franklin of three firefighters raising it amid the rubble of the World Trade Center after the September 11, 2001 terrorist attack on New York City. (Photo by Mario Tama/Getty Images)
UNITED STATES - MAY 28: Mayor Michael Bloomberg addresses the Republican State Convention at the Sheraton New York Hotel on Seventh Ave. (Photo by Andrew Savulich/NY Daily News Archive via Getty Images)
NEW YORK - JUNE 14: National Aeronautics and Space Administration (NASA) astronauts Dominic Gorie (L) and Frank Culbertson (R) present an American flag to New York City Mayor Michael Bloomberg (C) in honor of Flag Day June 14, 2002 in New York City. The flag was found at Ground Zero, the location of the World Trade Center in New York, and was flown into space in December 2001 aboard the NASA Space Shuttle Endeavor. Culbertson was onboard the International Space Station September 11, 2001 when the terrorist attacks occurred in the U.S. (Photo by Mario Tama/Getty Images)
NEW YORK - JULY 4: New York City Mayor Michael Bloomberg gets a Nathan's Famous hot dog after Takeru Kobayashi won Nathan's Famous Fourth of July Hot Dog Eating Contest at Coney Island July 4, 2002 in the Brooklyn borough of New York City. Kobayashi, who won last year, set a new world record by eating 50 1/2 hot dogs in twelve minutes. (Photo by Mario Tama/Getty Images)
New York City Mayor Michael Bloomberg adjusts his tie as girlfriend Diana Taylor, right, laughs while on the observation deck of the Empire State building, Monday, Nov. 7, 2005. The latest polls show the incumbent Republican mayor leading his Democratic challenger Fernando Ferrer by 38 points. (AP Photo/Stephen Chernin)
New York City Mayor Michael Bloomberg greets supporters during a party for his election to a second term in New York, Tuesday, Nov. 8, 2005. (AP Photo/Gregory Bull)
New York Mayor Michael Bloomberg holds aloft "Alaska" the American Bald Eagle during the unveiling of Ireland's National Monument to the New York National Guard's 69th Infantry Regiment "the Fighting 69th" who fought with the Union forces in the American Civil War, and it's leader, Brigadier Michael Corcoran, in Ballymote, Ireland, Tuesday, Aug. 22, 2006. (AP Photo/Peter Morrison)
Police Chief Ray Kelly, forth from left, listens in as New York City Mayor Michael Bloomberg, center, speaks to reporters after a meeting with community leaders about a weekend shooting involving police. Police fired an estimated 50 rounds at Sean Bell, 23, and two other unarmed men in a car early Saturday, hours before he was to have married the mother of his two children. (AP Photo/Kathy Willens)
New York Mayor Michael Bloomberg, left, is surrounded by press as he visits the 311 call center in New York, Wednesday, June 20, 2007. A day after quitting the Republican Party and registering as unaffiliated, Bloomberg continued to send mixed signals about his intentions, discussing both his mayoral term and vowing to address the major issues facing the country. (AP Photo/Bebeto Matthews)
Abdus Salam, center, watch as British leader David Cameron, left, and New York Mayor Michael Bloomberg eat hotdogs from his stand during Cameron's visit to the city during his first U.S. trip, Wednesday July 21, 2010, in New York. (AP Photo/Bebeto Matthews)
New York City Mayor Michael Bloomberg, right, calls prospective voters in support of Rhode Island Independent gubernatorial candidate Lincoln Chafee, left, at the campaign headquarters in Warwick, R.I., Monday, Nov. 1, 2010. (AP Photo/Stew Milne)
New York Mayor Michael Bloomberg, left, and French President Nicolas Sarkozy converse in front of the Statue of Liberty before taking part in a ceremony in anticipation of the 125th anniversary of the monument on Liberty Island, Thursday, Sept. 22, 2011 in New York. (AP Photo/Jason DeCrow)
NEW YORK, NY - MAY 10: New York City Mayor Michael Bloomberg (2nd R) speaks with an aide while announcing a new emergency notification system at a news conference overlooking Ground Zero on May 10, 2011 in New York City. Bloomberg, who was joined by politicians, federal officials and the heads of mobile phone companies, spoke of the system that will alert what to do in case of emergency to anyone with an 'enabled' mobile device within range of a cell phone tower. Part of a law passed by Congress five years ago, the service is scheduled to be available in New York City and Washington, D.C. by the end of the year and is expected in the rest of the country by mid-2012. (Photo by Spencer Platt/Getty Images)
NEW YORK, NY - SEPTEMBER 07: New York Mayor Michael Bloomberg (R) speaks at a press conference as construction continues at the World Trade Center site on September 7, 2011 in New York City. The National September 11 Memorial & Museum will feature two reflecting pools on the footprints of the twin towers. The memorial is scheduled to be dedicated on September 11, 2011, the tenth anniversary of the World Trade Center terrorist attacks. (Photo by Mario Tama/Getty Images)
New York Gov. Andrew Cuomo, left, holds the Halas Trophy, while New York Mayor Michael Bloomberg, center, holds the Vince Lombardi Trophy as New York Giants quarterback Eli Manning, right, waves to the crowd during a ticker-tape parade celebrating the team's NFL football Super Bowl XLVI championship, Tuesday, Feb. 7, 2012, in New York. The Giants beat the New England Patriots 21-17 on Sunday, Feb. 5, in Indianapolis. (AP Photo/Julio Cortez)
Mayor Michael Bloomberg surveys the damage to a passenger ferry after it crashed on Wednesday, Jan. 9, 2013 in New York. At least 57 people were injured, two critically, when a commuter ferry struck a dock in New York City's financial district, ripping open a right-side front corner. (AP Photo/Bebeto Matthews)
WASHINGTON, DC - MARCH 02: (L-R) Los Angeles Mayor Antonio Villaraigosa, New York Mayor Michael Bloomberg and Chicago Mayor Rahm Emanuel participate in a forum about education in big cities at the Katzen Arts Center on the campus of American University March 2, 2012 in Washington, DC. Calling their municipalities 'city-states,' the mayors suppored the idea of individual school districts being able to compete with states for the $4.35 billion 'Race to the Top' grant program created by President Barack Obama. (Photo by Chip Somodevilla/Getty Images)
New York City Mayor Michael Bloomberg speaks at a gun violence summit at Johns Hopkins Bloomberg School of Public Health in Baltimore, Monday, Jan. 14, 2013, where he outlined his proposals for federal gun control reforms. Bloomberg urged President Barack Obama and Congress to increase background check requirements for firearms purchases, and also said the federal government needs to get tougher on gun trafficking. (AP Photo/Patrick Semansky)
NEW YORK, NY - OCTOBER 31: New York City Mayor Michael Bloomberg (C) rings the opening bell of the New York Stock Exchange on the first day of opening since Hurricane Sandy October 31, 2012 in New York City. The storm has claimed several dozen lives in the United States and has caused massive flooding across much of the Atlantic seaboard. U.S. President Barack Obama has declared the situation a 'major disaster' for large areas of the U.S. east coast, including New York City, with widespread power outages and significant flooding in parts of lower Manhattan and elsewhere. (Photo by Allison Joyce/Getty Images)
Mayor Michael Bloomberg, right, and artist Ugo Rondinone are framed in the in the rock sculpture "Human Nature," as they react during a press conference on Monday, April 22, 2013 in New York. Rondinone, a Swiss-born and New York based artist, created a public art installation of nine colossal human-shaped figures made of rough bluestone, that will transform New York's Rockefeller Plaza for seven weeks. (AP Photo/Bebeto Matthews)
NEW YORK, NY - MARCH 12: New York City Mayor Michael Bloomberg holds a large cup as he speaks to the media about the health impacts of sugar at Lucky's restaurant, which voluntarily adopted the large sugary drink ban, March 12, 2013 in New York City. A state judge on Monday blocked Bloomberg's ban on oversized sugary drinks but the Mayor plans to appeal the decision. (Photo by Allison Joyce/Getty Images)
New York Mayor Michael Bloomberg, left, and Democratic mayoral hopeful Bill de Blasio attend a 9/11 Memorial ceremony Wednesday, Sept. 11, 2013, marking the 12th anniversary of the 2001 terrorist attacks on the World Trade Center in New York. (AP Photo/Adrees Latif, Pool)
NEW YORK, NY - NOVEMBER 06: New York City Mayor-elect Bill de Blasio speaks with outgoing Mayor Michael Bloomberg at City Hall on November 6, 2013 in New York City. It was the first meeting between the two since de Blasio's election victory the day before. (Photo by John Moore/Getty Images)
CORRECTS LEFT TO RIGHT From right, Florence Mayor Matteo Renzi, New York Mayor Michael Bloomberg, London Mayor Boris Johnson, and Warsaw Mayor Hanna Gronkiewicz-Waltz, during the Mayors Challenge competition, at City Hall in London, Tuesday, Sept. 24, 2013. New York Mayor Michael Bloomberg is offering European cities millions of dollars to be government groundbreakers, tapping his personal fortune to extend his cities-as-civic-laboratories campaign overseas as the end of his own tenure nears. (AP Photo/Matt Dunham)
New York City Mayor-elect Bill de Blasio, left, join Mayor Michael Bloomberg for a meeting in the "Bull Pen," the mayor's main City Hall office, on Wednesday, Nov. 6, 2013, in New York. De Blasio, the public advocate, was trouncing Republican rival Joe Lhota 73 to 24 percent in incomplete, unofficial returns that were on pace to post one of the largest routs in the history of the nation's largest city. (AP Photo/Bebeto Matthews)
NEW YORK, NY - AUGUST 19: New York City Mayor Michael Bloomberg speaks at a press conference with United States Secretary for Housing and Urban Development Shaun Donovan (not seen), unveiling a Hurricane Sandy Recovery Report on August 19, 2013 in the Greenpoint neighborhood of the Brooklyn Borough of New York City. The report calls for strengthening the region's electrical grid, reinforcing coastline and protecting gas supplies. (Photo by Andrew Burton/Getty Images)
FILE - In this Jan. 27, 2016 file photo, former New York Mayor Michael Bloomberg talks with diplomats at U.N. headquarters. By wide margins, Americans of all ideologies say they have no interest in voting Bloomberg into the White House, suggesting that the billionaire media mogul would have significant headwinds should he mount a third-party bid for president. Just 7 percent of registered voters say theyâd definitely vote for him, while 29 percent say theyâd consider it, according to a new Associated Press-GfK poll. (AP Photo/Bebeto Matthews)
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Bloomberg noted that while he and Trump are on "friendly terms," he said the billionaire real-estate mogul "appeals to our worst impulses" as voters.
"He has run the most divisive and demagogic presidential campaign I can remember, preying on people's prejudices and fears," Bloomberg wrote. "Abraham Lincoln, the father of the Republican Party, appealed to our 'better angels.' Trump appeals to our worst impulses."
Bloomberg also criticized Trump's proposal to bar Muslims from entering the US and his comments on Mexican immigrants.
Threatening to bar foreign Muslims from entering the country is a direct assault on two of the core values that gave rise to our nation: religious tolerance and the separation of church and state. Attacking and promising to deport millions of Mexicans, feigning ignorance of white supremacists, and threatening China and Japan with a trade war are all dangerously wrong, too. These moves would divide us at home and compromise our moral leadership around the world. The end result would be to embolden our enemies, threaten the security of our allies, and put our own men and women in uniform at greater risk.
Bloomberg put Cruz in the same extreme camp as Trump.
"Senator Cruz's pandering on immigration may lack Trump's rhetorical excess, but it is no less extreme," Bloomberg wrote. "His refusal to oppose banning foreigners based on their religion may be less bombastic than Trump's position, but it is no less divisive."