In a television ad first reported Thursday by CNN, Bush called Trump a "jerk" twice while citing the real-estate mogul's mocking of a physically disabled reporter.
"When anybody --anybody -- disparages people with disabilities, it sets me off. That's why I called him a jerk," Bush said at the start of the 60-second spot.
PHOTOS: Jeb Bush on the campaign trail
Jeb Bush campaign
Jeb Bush releases 60-second TV ad attacking 'jerk' Donald Trump
NORTH CHARLESTON, SC - JANUARY 15: Former Republican presidential candidate and South Carolina Sen. Lindsey Graham (R) announces his endorsement of Jeb Bush for president on January 15, 2016 in North Charleston, South Carolina. Graham dropped his bid for the presidency last month. (Photo by Scott Olson/Getty Images)
NORTH CHARLESTON, SC - JANUARY 14: Republican presidential candidates (L-R) New Jersey Governor Chris Christie and Jeb Bush laugh during a commercial break during the Fox Business Network Republican presidential debate at the North Charleston Coliseum and Performing Arts Center on January 14, 2016 in North Charleston, South Carolina. The sixth Republican debate is held in two parts, one main debate for the top seven candidates, and another for three other candidates lower in the current polls. (Photo by Scott Olson/Getty Images)
GRINNELL, IA - JANUARY 12: Republican presidential candidate Jeb Bush greets people during a town hall at the Brownell's Firearms Manufacturing company on January 12, 2016 in Grinnell, Iowa. Bush continues his quest to become the Republican presidential nominee. (Photo by Joe Raedle/Getty Images)
WAUKESHA, WI - NOVEMBER 09: Wisconsin Governor Scott Walker (R) sits with Republican presidential candidate Jeb Bush (L) at La Casa de Esperanza during a campaign stop on November 9, 2015 in Waukesha, Wisconsin. Tomorrow Bush will participate in the third Republican presidential debate sponsored by Fox Business News and the Wall Street Journal at the Milwaukee Theater in nearby Milwaukee. (Photo by Scott Olson/Getty Images)
TAMPA, FL - NOVEMBER 2: Republican presidential candidate and former Florida governor Jeb Bush allows a supporter to loosen his necktie during a rally on his 'Jeb Can Fix It' Tour on November 2, 2015 at the Tampa Garden Club in Tampa, Florida. Following dropping poll numbers and poor debate performance Bush is trying to reset his campaign that many say has been flailing. (Photo by Brian Blanco/Getty Images)
DES MOINES, IA - AUGUST 14: Republican presidential hopeful and former Florida Gov. Jeb Bush (R) and Iowa Gov. Terry Branstad eat a pork chop on a stick at the Iowa Pork Tent during the Iowa State Fair on August 14, 2015 in Des Moines, Iowa. Presidential candidates are addressing attendees at the Iowa State Fair on the Des Moines Register Presidential Soapbox stage. The State Fair runs through August 23. (Photo by Justin Sullivan/Getty Images)
DES MOINES, IA - AUGUST 14: Republican presidential hopeful and former Florida Gov. Jeb Bush (C) talks with members of the media as U.S. Sen. Chuck Grassley (L) (R-IA) and U.S. Sen. Joni Ernst (R) (R-IA) look on during the Iowa State Fair on August 14, 2015 in Des Moines, Iowa. Presidential candidates are addressing attendees at the Iowa State Fair on the Des Moines Register Presidential Soapbox stage. The State Fair runs through August 23. (Photo by Justin Sullivan/Getty Images)
MIAMI, FL - JUNE 15: Former Florida Governor Jeb Bush waves on stage as he announces his candidacy for the Republican presidential nomination during an event at Miami-Dade College - Kendall Campus on June 15 , 2015 in Miami, Florida. Bush joins a list of Republican candidates to announce their plans on running against the Democrats for the White House. (Photo by Joe Raedle/Getty Images)
MYRTLE BEACH, SC - MARCH 18: Former Florida Governor and potential Republican presidential candidate Jeb Bush kisses a supporter during an early morning GOP breakfast event on March 18, 2015 in Myrtle Beach, South Carolina. Bush announced in December that he 'actively explore' a presidential run in 2016. He is currently on a two day tour through South Carolina and will attend several fundraising events. (Photo by Richard Ellis/Getty Images)
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The ad also finished with Bush repeating the line and asking, "What kind of person would you want to have in the presidency that does that? At what point do we say, 'Enough of this?'"
At a November campaign rally, Trump sparked intense backlash when he dramatically impersonated the reporter supposedly retracting an old story that Trump claimed had validated his claim that Muslims in New Jersey celebrated the September 11, 2001, terror attack. Trump passionately denied knowing the journalist or mocking his disability, but the reporter in question, The New York Times' Serge Kovaleski, said Trump knew exactly what he was doing.
CNN reported that the new Bush ad is running in New Hampshire.