In Arizona, six-term U.S. Sen. John McCain could be in the political battle of his life.
Polls show a super-tight race as Arizona's senior senator faces a hot challenge from his Democratic opponent, U.S. Rep. Ann Kirkpatrick.
A Real Clear Politics polling average taken from March 7 through April 11 has McCain up by just 0.5 points, making their likely general election match-up race a statistical tie.
While McCain, a Vietnam War hero and Senate leader, has a solid national profile after his multiple presidential bids, some in his state party have said enough to the feisty politico.
The Republican Party in Maricopa County last summer approved a resolution calling on voters to support "anyone but McCain." And in recent weeks, ahead of his Aug. 30 primary, he's made the short list of Senate seats that could be up for grabs in November's election.
Sabato's Crystal Ball of the University of Virginia's Center for Politics described the U.S. Senate race in Arizona as "leans right," but adds that it could be a tough battle ahead.
"While the Senate will probably be won or lost in presidential swing states, ...it would not be a complete shock if Republicans ultimately had to work very hard to hold onto this seat," wrote Sabato's Crystal Ball editor Geoffrey Skelley in assessing the Arizona race.
With 34 Senate seats open in this election cycle, the top of the ticket could be harmful for Republicans as voters seem now split between Donald Trump and U.S. Sen. Ted Cruz as their delegate fight continues. Some political experts think if Trump wins the nomination, Democrat chances for victory, especially in Congressional races, may increase.
Kirkpatrick, in her campaign ads, has tied McCain to Trump. McCain has said he will support whoever is the eventual nominee.
Kirkpatrick, 66, and a native of McNary, Arizona, is in the middle of her second Congressional term, representing the state's First Congressional District from 2009 to 2011, losing her seat, and then winning it back to return to Washington in 2013. She is a mother of four and an attorney.
McCain, 79, has served in the House and Senate for 35 years. He told reporters Tuesday that he might not attend his party's nominating convention in August, saying that "I have to campaign for re-election." He has held a coveted speaker spot at the party's convention for several years.
McCain's campaign had $5.5 million cash on hand at the end of March, according to his Federal Election Commission filing covering Jan. 1 to March 31. Kirkpatrick had significantly less, reporting $856,755 cash on hand from the same reporting period.
Kim Fridkin, a professor at Arizona State University's School of Politics and Global Studies, says she believes Kirkpatrick still has "an uphill battle" in the election with McCain enjoying the perks of a longtime incumbent, including high name recognition and also fundraising.
But, Fridkin observes, the demographics of her state have changed it from red to nearly purple. While the Arizona Republican Party is conservative, "we have a lot of new voters here, legal immigrants and also people moving from other states, from California and the Midwest. There are a lot more independents here than even 10 years ago and also a lot more Democrats."
She said that in a previous U.S. Senate campaign in Arizona, when Jeff Flake ran for an open seat, the race against his Democratic opponent was fairly close. "That kind of feeds into the fact that the state is more evenly balanced than some recognize."
In this election, Kirkpatrick's tactic is to push the idea that McCain hasn't really taken care of the state, focusing his interests more on national and international issues than those back home.
McCain, Fridkin adds, is not only facing a contested primary with three opponents struggling to raise their name identification, which he is likely to win, but "it's unusual in that he doesn't have as much of a support among his partisans as he would have in other states."
She adds: "John McCain isn't really popular among Republicans in Arizona."
The big question looming ahead is how a presidential election might impact McCain's bid for a seventh term. "I'm not sure how the general election will unfold," Fridkin said. "If Trump is the nominee, that could motivate a lot of Latino voters here to come out and vote for the Democrat. That could be important."