In the past, getting reelected was never a problem for Sen. Susan Collins. The Maine Republican, who was first elected to the U.S. Senate in 1996, was reelected by 17% in 2002, 23% in 2008 and 37% in 2014. But that was before the incredibly divisive presidency of Donald Trump. And journalist David Sharp, in a report for the Associated Press (AP), stresses that Trump could be the “biggest hurdle” in Collins’ battle to win a fifth term.

In the past, Collins — who is conservative but not far-right — was quite popular in Maine, a blue state. But distancing herself from Trump’s controversies and far-right agenda has proven difficult for Collins. And Sharp notes that thanks to the impeachment inquiry Trump is facing, Collins might be forced to take a stand on whether or not he should remain in the White House: if Trump is impeached in the U.S. House of Representatives, the 66-year-old senator would later be asked to vote “guilty” or “not guilty” on articles of impeachment in a Senate trial.

David Farmer, a Democratic operative in Maine, told AP, “Susan Collins is in a terrible position. The position that she’s in where she will likely.… take a vote on whether to remove the president from office is going to inflame either the Democratic or the Republican base.”

On one hand, voting to remove Trump from office would infuriate Trump and his Republican supporters. But on the other hand, voting “not guilty” on articles of impeachment would give Maine Democrats yet another reason to attack Collins — who angered Democrats in her state by voting for the confirmation of U.S. Supreme Court Justice Brett Kavanaugh in 2018. Maine Democrats have been asserting that a vote for Collins next year would be a vote for Trump.

Collins is facing a GOP primary challenge from pro-Trump activist Derek Levasseur. While Democrats are attacking Collins as pro-Trump, Levasseur argues that she isn’t pro-Trump enough. If Collins defeats Levasseur in the primary and makes it to the general election, the Democrat she might be going up against is Sara Gideon — speaker of the Maine House of Representatives. Gideon, who has been endorsed by the Democratic Senatorial Campaign Committee, seems most likely to win the nomination.

But Gideon isn’t the only Democratic candidate hoping to take on Collins in 2020: others include attorney Bre Kidman, activist Betsy Sweet and Google executive Ross LaJeunesse. Gideon has been criticizing Collins for not standing up to Trump more, and if she does end up competing with Collins in the general election next year, the Maine House speaker will no doubt continue to attack her as too favorable to Trump.

Collins, who has said that she didn’t vote for Trump in 2016, told AP that she is troubled by how bitter the partisan divisions have become in the United States.

“The current environment is very disturbing to me,” Collins asserted. “There’s a lack of focus on what we need to do for the American people, and instead, the focus is on power struggles over who’s going to control what.”

One of Democrats’ top goals in 2020 — along with defeating Trump — is achieving a majority in U.S. Senate. In order to retake the Senate, Democrats would need to flip four GOP-held seats while holding all of the seats they are defending. And Collins is among the incumbent Senate Republicans who is often described as vulnerable, along with Sen. Cory Gardner of Colorado, Sen. Martha McSally of Arizona and Sen. Joni Ernst of Iowa.