Three high-profile incumbents trying to hold on to their jobs in Tuesday's primaries have done so despite facing tough opposition.
Florida's GOP Sen. Marco Rubio and Democratic Rep. Debbie Wasserman Schultz and Arizona Republican Sen. John McCain beat back primary challengers, according to the Associated Press.
While favored to win, the establishment officials faced stiffer-than-usual challenges as the bitter and unpredictable presidential race enters its final post-Labor Day push.
McCain, who was first elected senator in 1986 and served as his party's presidential nominee in 2008, edged out tea party conservative challenger Kelli Ward and two other Republicans on the ballot. But the Vietnam War veteran had to deal with a tough fight in a contest highlighting his often uncomfortable relationship with Republican standard-bearer Donald Trump.
RELATED: John McCain's military capture and rescue
John McCain military capture and rescue
John McCain military capture and rescue
A photo taken by a French cameraman in 1967 shows US Navy Airforce Major John McCain lying on a bed in a Hanoi hospital as he was being given medical care for his injuries. John McCain was captured in 1967 at a lake in Hanoi after his Navy warplane was downed by the Northern Vietnamese army during the Vietnam War.
P368426 01: (File Photo) Senator John Mccain Is Pulled Out Of A Hanoi Lake By North Vietnamese Army Soldiers And Civilians October 26, 1967 In Hanoi, North Vietnam. Mccain's A-4E Skyhawk Was Shot Down By A Surface-To-Air Missile. Mccain Broke Both Arms And His Right Knee Upon Ejection And Lost Consciousness Until He Hit The Water. (Photo By Getty Images)
P368426 04: (File Photo) Senator John Mccain In A Hanoi Hospital During The Vietnam War November, 1967. (Photo By Getty Images)
P368426 06: (File Photo) A Statue Commemorating October 26, 1967, The Day Lt. Cmdr. John Mccain Was Captured By The North Vietnamese Army, Stands In Hanoi, North Vietnam. (Photo By Getty Images)
P368426 05: (File Photo) A Mug Shot Of Senator John Mccain As A P.O.W. Taken By The North Vietnamese Sometime Between 1967-73 (Photo By Getty Images)
HANOI, VIET NAM: This file picture taken in 1967 shows US Navy Airforce Major John McCain lying on a bed in a Hanoi hospital as he was being given medical care for his injuries. McCain was captured in 1967 at a lake in Hanoi after his Navy warplane was downed by the Northern Vietnamese army during the Vietnam War. One of his rescuers said 24 February 2000, McCain was well treated after being pulled from the lake by villagers. McCain said that upon capture he was beaten by an angry mob and bayoneted in the groin. (B/W ONLY) AFP PHOTO (Photo credit should read AFP/Getty Images)
U.S. Naval Lt. Commander John S. McCain III, son of the Navy's Commander-in-Chief in Europe and grandson of the Navy's greatest World War II carrier commanders, is show in July, 1967, in Vietnam. (AP Photo)
John McCain walks outside the Hoa Lo prison, nicknamed "The Hanoi Hilton" in Hanoi, Vietman on April 26, 2000 where McCain was kept as a prisoner of war from October 1967 until March 1973. McCain was visiting as Vietnam marked the 25th anniversary of the end of the war. (AP Photo/David Guttenfelder)
John McCain walks inside the Hoa Lo prison, nicknamed "The Hanoi Hilton" in Hanoi, Vietman on April 27, 2000 where McCain was kept as a prisoner of war from October 1967 until March 1973. McCain was visiting as Vietnam marked the 25th anniversary of the end of the war. (AP Photo/David Guttenfelder)
Sen. John McCain, R-Ariz., tells his son Jack about his time as a Vietnam war P.O.W. as they look into a prison cell at the Hoa Lo prison, nicknamed "The Hanoi Hilton" by American prisoners, during a visit in this April 26, 2000 file photo. McCain was a P.O.W. from October 1967 to March 1973 and spent 3 years locked in the Hoa Lo. McCain, his wife Cindy, and son were visiting Vietnam as the country prepares to mark the 25th anniversary of the end of the war on April 30. (AP Photo/David Guttenfelder, File)
U.S. Sen. John McCain, R-Ariz, is seen during a tour of Hoa Lo Prison site, Hanoi, Vietnam, Wednesday, April 8, 2009. The photo behind McCain is that the Hanoi army and people pull out McCain out of Truc Back Lake on Oct. 26, 1967 after his plane was shot down. (AP Photo/Chitose Suzuki)
Mai Van On gestures to U.S. Senator John McCain, left, on Wednesday, Nov. 13, 1996 while describing how he pulled on McCain's parachute to save him from Hanoi's Truc Bach lake in 1967. McCain, then a U.S. bomber pilot in the Vietnam War, was shot down over Hanoi 29 years ago. (AP Photo/Hong Sam)
John McCain stands next to a monument marking the spot on the banks of Lake Truc Bach in Hanoi, Vietman on April 26, 2000 where McCain was pulled ashore after his plane was shot down in October 1967. McCain was visiting as Vietnam marked the 25th anniversary of the end of the war. (AP Photo/David Guttenfelder)
Lt. Commander John S. McCain III, 30, right, shown in 1967, member of a famous U.S. Navy family and an aircraft carrier pilot, was shot down and captured in Hanoi. His father, John S. McCain Jr., center, is the U.S. Navy's commander in chief in Europe. His granfather, left, Adm. John S. McCain, commanded all U.S. aircraft carriers in the Pacific during World War II. (AP Photo)
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Last year, Trump suggested that McCain's accolades as a war hero were overblown, and earlier this month, Trump refused to endorse McCain, accusing him of failing to do "a good job" for veterans. He later reversed his decision in favor of backing McCain.
The Arizona senator must now steel himself for a general election race against Democratic Rep. Ann Kirkpatrick while sharing the ballot with a nominee whose approval ratings with minority voters have sunk to historic lows. In 2012, non-white voters made up 28 percent of Arizona's electorate.
In an interview with NBC News this week, McCain dismissed the idea that he must separate himself from Trump, whom he has endorsed. "It's the people of Arizona who know me," he said. "I have 100 percent name ID, they all know me very well, I've been here for many years. So I don't think their judgment is affected by anything but what they view of me, how they view me."
In Florida, Rubio easily prevailed Tuesday night over a challenge from anti-establishment millionaire candidate Carlos Beruff, according to projections by the Associated Press. Rubio won despite taking criticism for reversing his pledge during the Republican presidential primary not to seek re-election after his White House bid.
Rubio will face Patrick Murphy, the winner of the Democratic Senate primary, for one of November's most closely-watched downballot races. (Murphy, a Democratic Party favorite, squared off Tuesday night against liberal firebrand Alan Grayson, whose political fortunes sputtered after allegations of domestic abuse.)
Wasserman Schultz, the former leader of the Democratic National Committee, also hung on after a primary challenge Tuesday. Wasserman Schultz was forced to step down from the helm of the DNC in July amid allegations that she and other Democratic officials had worked to thwart the primary hopes of presidential candidate Bernie Sanders.
Sanders endorsed her challenger, Tim Canova, and backers of the Vermont senator shoveled nearly four million dollars of donations into Canova's war chest.