AUSTIN, Texas (AP) — The 2022 midterm election season opens Tuesday in Texas, where voters will pick their nominees for governor, attorney general, congressional seats and more.

With the next state primaries not coming until May, Texas will be far ahead in offering the first glimpse of whether embracing former President Donald Trump remains a litmus test for Republicans and what messages are sticking for Democrats.

Of particular interest are congressional primaries in two districts where the incumbents are threatened. Democratic Rep. Henry Cuellar is facing a progressive challenger just weeks after FBI agents raided his home.  Republican Rep. Van Taylor is seen as vulnerable in his GOP-dominant district for criticizing the Jan. 6 insurrection and voting to certify Trump's loss in the 2020 election.

Statewide, Attorney General Ken Paxton is looking to survive a Republican primary challenge while under the cloud of an FBI investigation over corruption allegations.

What to watch as the Texas primary unfolds:

WHAT ISSUES ARE DRIVING THE TEXAS RACES?

Republican candidates in Texas are increasingly moving to the right, and some haven't stopped questioning the legitimacy of the 2020 presidential election — despite a broad coalition of top government and industry officials calling it the "most secure in American history."

That makes Texas' primary an early test of Trump's sustained influence on the party and how much discredited claims of widespread voter fraud will motivate Republican voters this year. One survey by Hearst Newspapers of Texas GOP congressional candidates found dozens who dispute the outcome of President Joe Biden's victory. 

The primary also marks six months since Texas put in place the most restrictive abortion law in the U.S. in nearly 50 years. Democrats have said abortion rights will be a centerpiece of their national strategy in the 2022 midterms, but the issue has not been at the forefront  in Texas' primary.

ARE THE FIRST SHAKE-UPS IN CONGRESS AHEAD?

Cuellar and Taylor are facing tough primaries in their districts.

Cuellar, a nine-term incumbent and one of the most conservative Democrats in Congress, has long bucked his party by voting against abortion rights and gun control. That record has again put him in a tough reelection against progressive challenger Jessica Cisneros, who first ran against Cuellar two years ago.

Cisneros, a former intern of Cuellar's, came within 4 percentage points of an upset in 2020. Cuellar could be more vulnerable this time after FBI agents searched his home in January as part of an investigation that relates to the former Soviet Republic of Azerbaijan. 

Cuellar has denied wrongdoing and hasn't been charged with a crime.

A Cisneros win deep in South Texas would rank among the biggest upsets to date for the party's progressive wing. It could also entice Republicans to mount a sudden and more serious run at flipping the district. 

For Republicans, Taylor is on the defense after his vote to create an independent commission to investigate the Jan. 6 insurrection by a mob of Trump supporters. His predicament shows how the GOP has diminished the gravity of the Capitol attack and sought to assign blame elsewhere.

IS THE TEXAS GOVERNOR'S RACE SET?

For months, Republican Gov. Greg Abbott and Democrat Beto O'Rourke have been looking past the primaries and campaigning against each other.

Abbott set his sights on a third term with Trump's endorsement, a formidable $56 million in campaign funds and his signature on a long list of divisive new laws — on guns, abortion and immigration — that have steered Texas hard to the right. 

But that didn't insulate him from challengers on the far right, including former Florida congressman Allen West, the one-term tea party firebrand. West and other primary rivals leaned into anger within the GOP base over Abbott's handling of the COVID-19 pandemic, including an early mask mandate. 

But there are scarce signs of a close race. If Abbott avoids a primary runoff by garnering more than 50% of the vote, his victory would demonstrate broad support within the GOP and keep him in the conversation of potential 2024 presidential candidates.

O'Rourke, coming off an early exit in the 2020 presidential race, has shown he can still draw a crowd in Texas and quickly raise money. He has no serious competition on Tuesday, though his performance along the U.S.-Mexico border will be closely watched.

During O'Rourke's 2018 run for U.S. Senate, he underperformed in South Texas in both the primary and general election. Republicans are making a strong push in that region after Trump flipped some border counties in 2020. High GOP turnout along the border during Tuesday's primary could be a warning sign for Democrats.

IS A TRUMP ALLY IN TROUBLE IN THE TEXAS PRIMARY?

The most heated statewide primary is the attorney general's race.

Paxton, seeking his third term in office, led a failed lawsuit to overturn the 2020 election and has been dogged by securities fraud charges and an FBI investigation into corruption allegations. He has broadly denied wrongdoing.

He carries Trump's endorsement and has become one of the nation's most prominent state attorneys general by bringing cases against the Biden administration and Big Tech.

His challengers, including Texas Land Commissioner George P. Bush and U.S. Rep. Louie Gohmert, are running on a message of restoring order to an office that has experienced upheaval under Paxton.

Bush, a son of former Florida Gov. Jeb Bush and a grandson of former President George H.W. Bush, has spent the final days of the race expressing confidence that he will force a May runoff. He's the only member of the Bush family still in public office.

WHAT WILL VOTING IN TEXAS BE LIKE?

Primary turnout is typically low in Texas, and this year so far has been no exception: Early voting has hovered in the low single digits among the state's 17 million registered voters. 

But this primary is also the first test of a GOP-engineered election overhaul that Texas Republicans muscled through the state Capitol last year. At least 17 other states this year will also hold elections under tougher rules, some driven by Trump's unfounded claims about the 2020 election. 

The rushed rollout of new rules for Texas' early primary has led to thousands of mail ballot applications and actual ballots getting returned for not including new identification requirements. 

Secretary of State John Scott has said voters are still learning the rules and expects Texas' later elections to run smoother. But local officials are worried that the issues could result in some voters not casting a ballot.