Sen. Susan CollinsSusan Margaret CollinsThe Hill’s Morning Report – Trump trial begins with clashes, concessionsSenate Republicans muscle through rules for Trump trialCollins breaks with GOP on attempt to change impeachment rules resolutionMORE is walking a fine line in President TrumpDonald John TrumpRouhani says Iran will never seek nuclear weaponsTrump downplays seriousness of injuries in Iran attack after US soldiers treated for concussionsTrump says Bloomberg is ‘wasting his money’ on 2020 campaignMORE’s Senate impeachment trial: The moderate Maine Republican has to demonstrate some independence from the president, but she cant run too far away from him and alienate GOP voters.

One of the most vulnerable lawmakers up for reelection this fall, Collins was the only GOP senator early Wednesday morning to break with her party and back a proposed rules change offered by Minority Leader Chuck SchumerCharles (Chuck) Ellis SchumerDemocratic senator blasts ‘draconian’ press restrictions during impeachment trialFeds seek 25-year sentence for Coast Guard officer accused of targeting lawmakers, justicesClinton: McConnell’s rules like ‘head juror colluding with the defendant to cover up a crime’MORE (D-N.Y.). 

Collins was also among the small band of centrist Republicans who successfully pressured Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellTrump admin releases trove of documents on Ukrainian military aidThe Hill’s Morning Report – Trump trial begins with clashes, concessionsWhat to watch for on Day 2 of Senate impeachment trialMORE (R-Ky.) to alter the trial rules in favor of greater transparency. 

Yet Collins also joined Republicans on 10 other votes that blocked Democratic amendments, proving to be a loyal foot-soldier on the majority of the votes.

All of these headline-grabbing actions underscored the strange position Collins finds herself in as she seeks her fifth term in the battleground state of Maine, which favored Hillary ClintonHillary Diane Rodham ClintonThe Hill’s Morning Report – Trump trial begins with clashes, concessionsTrump on Clinton’s Sanders comments: ‘She’s the one that people don’t like’Hillary Clinton tears open wound with her attack on SandersMORE by nearly 3 percentage points in 2016 but maintains strong support for Trump among its Republican base. 

That balancing act is nothing new for Collins, who has burnished a reputation as a moderate critics say undeservingly  even as shes historically been a reliable vote for the agenda of party leaders. 

Susan always does whats best for her constituents and then she explains it really well, Sen. Kevin CramerKevin John CramerSenate Republicans muscle through rules for Trump trialSenate braces for bitter fight over impeachment rulesSenate GOP mulls speeding up Trump impeachment trial MORE (R-N.D.), a Trump ally, told The Hill on Wednesday. Im sure it didnt hurt her any; Im sure it helped her. Shes a very courageous Republican.

Her fellow Maine senator, independent Angus KingAngus KingCongress struggles on rules for cyber warfare with IranDemocrats brace for round two of impeachment witness fightThe Hill’s Morning Report – Deescalation: US-Iran conflict easesMORE, declined to comment about Collinss political motivations for breaking with her party and Trump, whose disapproval rating in Maine sits at 52 percent according to a recent Morning Consult poll.

But King praised the rules changes that Collins and Sens. Lisa MurkowskiLisa Ann MurkowskiSenate Republicans muscle through rules for Trump trialSenate blocks push to subpoena Bolton in impeachment trialImpeachment trial begins with furor over rulesMORE (R-Alaska) and Rob PortmanRobert (Rob) Jones PortmanThe Hill’s Morning Report – Trump trial begins with clashes, concessionsSenate Republicans muscle through rules for Trump trialBiden campaign releases video to explain ‘what really happened in Ukraine’MORE (R-Ohio) helped secure from McConnell during a private lunch on Tuesday. The last-minute changes allowed for evidence from the House investigation to be automatically admitted to the Senate trial, and extended the number of days for both the prosecution and defense teams to make their arguments.

It was a good change. It solved two of the three problems with the rules, King, who defeated Collins in the 1994 race for the Maine governors mansion, told The Hill. Unfortunately it didnt solve the problem of reversing the witness-calling piece, but at least got the record squared away of not [having] such long, 12-hour days for opening arguments.

Democrats remain highly skeptical of Collins, doubtful she will ultimately side with them on upcoming critical votes to call witnesses and convict Trump.

They say they plan to use her past impeachment remarks as well as her vote to confirm Supreme Court Justice Brett KavanaughBrett Michael KavanaughHow Citizens United altered America’s political landscapeOvernight Health Care: Justices won’t fast-track ObamaCare case before election | New virus spreads from China to US | Collins challenger picks up Planned Parenthood endorsement Progressive group targets Collins over vote for Kavanaugh in new digital ad campaignMORE to paint the moderate senator as increasingly political and partisan. 

It speaks to a larger argument about Collins that she has changed during the couple of decades that shes been in Washington and become more partisan, more political, said a Democratic strategist. 

The impeachment proceedings in the Senate come as recent polling shows the senators support declining among voters in the Pine Tree State. A Morning Consult poll released last week showed Collins as the most unpopular senator in the chamber with a 52 percent disapproval rating, handing Democrats an obvious opening. 

Collins is facing five Democratic challengers, including Sara Gideon, the speaker of Maine’s House of Representatives. 

Moreover, the same poll commissioned by Senate Majority PAC found that 51 percent of Maine voters said that if Collins votes to acquit Trump, she would be doing so for political purposes.

The poll by Senate Majority PAC, a super PAC dedicated to helping Democrats, also showed a majority of voters believe Trump abused his power by pressuring Ukraine to investigate former Vice President Joe BidenJoe BidenSanders joins Biden atop 2020 Democratic field: pollThe Hill’s Morning Report – Trump trial begins with clashes, concessionsTrump says impeachment lawyers were ‘really good’MORE, a top political rival.

The Democratic Senatorial Campaign Committee (DSCC) is salivating at the chance to hit Collins over impeachment. The Democrats campaign arm this month launched a new website, drawing attention to remarks Collins made during former President Clinton’s impeachment trial in the late 1990s and comparing them to her statements about Trumps trial in the Senate. 

The website, titled whatchangedsusan.com, highlights comments from Collins in 1999, in which she said she needed witnesses and further evidence in order for the Senate to get to the truth so it could carry out its duty to do impartial justice.

Collins later voted against impeaching Clinton. 

Republicans say the move by Democrats to bring impeachment into the 2020 election is a miscalculation, arguing that it’s not front of mind for voters in Maine. 

This impeachment thing is going to be a nothing-burger, a Republican strategist told The Hill. Thats not where the debate is right now in Maine. 

Were talking about ethics. Were talking about taxes. Were talking about health care. Those are the issues people actually care about, the strategist continued. 

Collins has been widely praised for being a maverick figure in the past. She notably bucked her own party in 2017 when she voted against Republican efforts to repeal and replace the Affordable Care Act. 

However, her vote to confirm Kavanaugh in 2018 led to a number of progressive groups taking aim at Collins, vowing to unseat her. 

The most recent group, Demand Justice, targeted Collins in an ad Tuesday over her vote to confirm Kavanaugh over a year ago. 

For so long, she when combined with [former] Sen. Olympia Snow [R-Maine] were these Maine state treasures who had built a lot of trust and a lot of love, and a lot of regard in Maine and across the country, Democratic strategist Jon Reinish told The Hill. 

Over the last couple of years, Susan Collins has very, very demonstrably strayed from that past, he continued. I dont know whether its true colors coming out at the end of her career or the pressure of having a Republican president, and then being in the majority.

Still, Republicans say that Collinss decision on these issues is not necessarily going to cost her swing votes in the state. 

If someones not voting for Susan Collins because of Brett Kavanaugh, they probably werent going to vote for her anyways, the GOP strategist said. 

Jordain Carney contributed to this report