Sept 5 (Reuters) -

Texas Attorney General Ken Paxton, the state's top law-enforcement official, could lose his job in an impeachment trial on corruption charges led by his fellow Republicans that begins on Tuesday.

Paxton has been suspended from his position since the Republican-led Texas House of Representatives voted to impeach him on 20 corruption charges in May, including aiding a donor and persecuting whistleblowers.

Now his fate rests with the state Senate, also controlled by Republicans, which will vote on whether to remove him.

Paxton, who is under investigation by the FBI, has denied any wrongdoing and says the impeachment drive is a political witch hunt.

The trial, which is likely to last several weeks, could expose a split among the state's Republicans that echoes the national party's divisions over former U.S. President Donald Trump, who leads polling for his party's 2024 presidential nomination despite four criminal prosecutions.

Paxton, 60, has been elected three times despite legal woes that stretch back to 2015.

As attorney general, he has backed powerful oil and gas interests and pursued restrictions on

abortion

and

transgender rights. He has led Republican state opposition to Democratic President Barack Obama's policies and filed a lawsuit seeking to overturn Trump's 2020 election defeat.

Paxton's impeachment was triggered by his request that House lawmakers approve a $3.3 million settlement he reached with four former staff members who accused him of abuse of office and were subsequently fired. Lawmakers did not respond to the request.

The Texas House voted 121-23 to impeach him on 20 articles that accuse him of improperly aiding a wealthy political donor, conducting a sham investigation against the whistleblowers in his office, and covering up wrongdoing in a separate federal securities fraud case, among other offenses.

Paxton's trial in the 31-member Senate is expected to last for several weeks. All 12 Democrats are expected to vote against him, meaning nine Republicans would need to oppose him to reach the two-thirds majority necessary to permanently remove him from office.

Former Republican Texas Governor and two-time presidential candidate Rick Perry wrote in the Wall Street Journal last month that senators have a duty to set aside politics and look hard at all the evidence.

Jonathan Stickland, who heads a political action committee that is backed by three billionaire oil tycoons, has said he will work to ensure Republicans who oppose Paxton face a well-funded primary opponent in their next election.

Bob Stein, a political scientist at Rice University, says that pressure could help Paxton win acquittal.

"If senators want to hold onto their seats, let alone do something in the future like run for Congress, they have to watch carefully what they do because of these political donors backing Paxton," Stein said.

But Cal Jillson, a political scientist at Southern Methodist University, pointed to the lopsided House vote as a sign that Paxton might not hold on to his job.

"There is great security in crowds. The crowd of Republicans that voted to impeach him in the House and those that will likely vote against him in the Senate are going to be harder to punish," Jillson said.

(Reporting by Brad Brooks in Longmont, Colorado; Editing by Donna Bryson and Andy Sullivan)