McCain, Rubio, Wasserman Schultz face Tuesday Primary Tests

WASHINGTON, DC - NOVEMBER 10:  Senate Armed Services Committee Chairman John McCain (R-AZ) (C) talks with reporters after the National Defense Authorization Act passed 93-1 at the U.S. Capitol November 10, 2015 in Washington, DC. Congress is sending the $607 billion defense spending bill back to President Barack Obama after he vetoed an earlier version.  (Photo by Chip Somodevilla/Getty Images)

WASHINGTON, DC – NOVEMBER 10: Senate Armed Services Committee Chairman John McCain (R-AZ) (C) talks with reporters after the National Defense Authorization Act passed 93-1 at the U.S. Capitol November 10, 2015 in Washington, DC. Congress is sending the $607 billion defense spending bill back to President Barack Obama after he vetoed an earlier version. (Photo by Chip Somodevilla/Getty Images)

WASHINGTON  — Both Republican and Democratic incumbents face challenges from their respective party’s insurgent wing in Tuesday primaries, as GOP Sen. John McCain and Democrat Rep. Debbie Wasserman Schultz battle to retain their spots in Congress.

In Arizona, McCain faces a test from Kelli Ward, a conservative 33 years McCain’s junior who has suggested his age (he turned 80 on Monday) means he’s too old for a sixth term.

In Florida, the former Democratic National Committee chairwoman, Wasserman Schultz, must stave off a challenge for her congressional seat from Bernie Sanders-backed Tim Canova.

And first-term Republican Sen. Marco Rubio will face off against wealthy businessman Carlos Beruff — while on the Democratic side, Rep. Patrick Murphy and Rep. Alan Greyson square off to oppose the winner of the Rubio-Beruff race in November.

Four incumbents have already lost this year — with Republican Reps. Renee Ellmers of North Carolina, Randy Forbes of Virginia and Tim Huelskamp of Kansas and indicted Democratic Rep. Chaka Fattah going down in primaries.

Here’s what to watch on a day that could claim more incumbents:

Arizona Senate race

McCain had a clear lead of 55% to 29% over Ward in a CNN/ORC poll of likely voters two weeks ago — with a margin of error of plus or minus 5 percentage points.

But even years after his choice of Sarah Palin as his 2008 presidential running mate helped inspire the tea party movement, McCain still must defend his conservative credibility against a hardline opponent.

And his party’s presidential nominee, Donald Trump, has called McCain — a Navy veteran and prisoner of war in Vietnam — weak on veterans’ issues.

Ward, a physician, has used McCain’s 80th birthday to call him “old” and “weak” in national interviews.

“John McCain has stayed in Washington, D.C., for way too long — almost four decades,” she told CNN’s Brooke Baldwin last week, saying that McCain and his own family members had reservations about his age. “The Arizona voters will decide if they want an 80-year-old senator or not.”

Ward hit the same theme Monday in an interview with CNN’s Wolf Blitzer, saying: “I do want to give him the best 80th birthday present ever: the gift of retirement.”

Polls close in Arizona at 9 p.m. Eastern.

Wasserman Schultz’s test

Already on thin ice with her party’s left wing — mostly Sanders supporters who believed she favored Hillary Clinton in the primary — Wasserman Schultz was imperiled when the Wikileaks hack of Democratic National Committee emails became public.

She was forced to announce her planned resignation on the eve of the Democratic convention in Philadelphia, suffering a major public embarrassment a little more than a month before her primary.

Sanders has lent his mailing list to Canova, though he didn’t campaign with him in the weeks preceding the primary there.

“We’ve really got so much grassroots energy coming our way right now. The momentum is all on our side,” Canova told CNN’s Wolf Blitzer in a Monday interview.

Florida Senate primaries

Since Rubio reversed his decision to retire, he and Murphy, the Democratic congressman, have been largely focused on each other — each expecting to sail through primaries.

Beruff spent $7 million of his own money, but never closed the gap with Rubio.

Grayson, meanwhile, has had a hard time winning over voters amid reports he abused his ex-wife. He’s also been badly outraised by Murphy.

Polls close in Florida at 7 p.m. Eastern.