WASHINGTON (AP) — Is there a future in politics for Republicans who cross President Donald Trump?

The signs this year suggest no, and Trump has convinced his voters to defeat his adversaries again and again. The next test of the president's power to extract retribution is on Tuesday, when Rep. Thomas Massie of Kentucky faces a Trump-backed primary challenger.

Massie has been a thorn in the president's side for pushing for the release of the Jeffrey Epstein files, opposing the war with Iran and voting against Trump's signature tax legislation last year.

Here are some things to watch as voters in Alabama, Georgia, Idaho, Kentucky, Oregon and Pennsylvania cast ballots on Tuesday.

Will Trump's endorsement continue to carry the day?

Trump has repeatedly shown that Republican primary voters will follow his lead, even as his popularity wanes with the broader electorate.

In Kentucky, he's supporting first-time candidate Ed Gallrein over Massie, who has been in office since 2012. Massie is trying to convince Republicans that they can support both himself and Trump at the same time, a proposition that has been tried unsuccessfully in other races around the country.

On Saturday, Republican Sen. Bill Cassidy of Louisiana failed to even make the runoff, unable to repair his relationship with Trump five years after voting to convict him during his second impeachment trial. And earlier this month, Trump successfully dislodged five of seven Indiana Republicans he targeted for voting against his redistricting plan.

Trump is flexing his influence in other places on Tuesday as well.

WATCH: Tamara Keith and Amy Walter on Trump's power in pushing out 'disloyal' Republicans

In the race for Georgia governor, Trump is backing Lt. Gov. Burt Jones in an unexpectedly ugly battle for the Republican nomination. Jones, who comes from a wealthy Georgia family, has given his campaign $19 million. But billionaire Rick Jackson, a health care tycoon, has put more than $83 million of his fortune into the race. Trump's endorsement power has rarely been tested against that level of lopsided spending.

Trump stayed on the sidelines of Georgia's Senate race, leaving a crowded field of hopefuls seeking to take on Democratic Sen. Jon Ossoff, who's running unopposed for his party's nomination. But in Alabama, Trump endorsed Rep. Barry Moore for Senate to replace Tommy Tuberville, who is running for governor.

A test for Shapiro in Pennsylvania

It's no secret that Pennsylvania Gov. Josh Shapiro may run for the White House.

But on Tuesday, the Democrat's political clout will be tested in his home state, where he's working to elect a slate of House candidates that he thinks will give his party the best chance to flip Republican seats in the fall.

Shapiro's endorsed candidates include Paige Cognetti, mayor of Scranton; Bob Brooks, president of the state firefighters' union; and Janelle Stelson, a former television news personality who narrowly lost two years ago.

As popular as he may be, Shapiro's endorsements haven't scared off Democratic rivals, who are fighting to defeat the governor's picks — and perhaps send a message that he's not as strong as he'd like to be with the 2028 presidential contest looming.

Politically homeless in Georgia?

Georgia is about to feature a fresh case study in the divergent paths available to Republicans who defy Trump.

Secretary of State Brad Raffensperger and former Lt. Gov. Geoff Duncan were among the few Republicans to speak out against Trump's attempt to overturn his 2020 loss.

Both are now running for governor — Raffensperger as a Republican and Duncan as a Democrat — and both are trying to convince voters to look past things they said in the past.

Raffensperger is spending millions of his own money trying to reintroduce himself to Republicans by reminding them of his long career in conservative politics before defying Trump.

Duncan, meanwhile, is trying to convince Democratic voters that they can trust him after renouncing his prior opposition to abortion rights, gun control and the expansion of Georgia's Medicaid program.

The primaries will go to a runoff on June 16 if nobody gets 50% of the vote on Tuesday.

Chaos in Alabama?

Confusion may reign across Alabama on Tuesday as votes cast in four of the state's seven congressional districts may not be counted.

That's because Republican Gov. Kay Ivey moved just last week to postpone the primaries until Aug. 11, emboldened by the recent U.S. Supreme Court decision that hollowed out the Voting Rights Act. Republicans across Alabama, Louisiana and Tennessee are now scrambling to redraw congressional boundaries to eliminate some majority-Black U.S. House districts to maximize their political advantage.

Over the weekend, thousands of civil rights activists rallied in Alabama against the changes, but the redistricting plan is moving forward.

That means that ballots cast Tuesday in primaries for Alabama's 1st, 2nd, 6th and 7th congressional districts will be voided, the secretary of state says, while state officials restore a previous set of Republican-drawn district boundaries.

You'd be excused for being confused. Alabama voters will still choose nominees Tuesday as planned for the 3rd, 4th and 5th congressional districts, as well as for U.S. Senate and a full slate of state and local offices.

Rep. David Scott's death is a reminder of Democratic gerontocracy

The late Rep. David Scott, D-Ga., was the fourth Democrat to die in office this term, fueling a growing restlessness on the left over the party's aging leadership. Scott, who was 80 when he died, was seeking a 13th term.

Scott's name will appear on the ballot alongside five other candidates running in the Democratic primary, but votes for him will not be counted. Whether someone wins on Tuesday or the race goes to a runoff on June 16, the Democratic nominee is almost certain to win the general election in a district that tilts overwhelmingly toward the Democrats.

A special election on July 28 will decide who finishes the remainder of Scott's term, with a runoff on Aug. 25 if nobody gets a majority.