Senators Susan Collins is seen walking from the Senate subway to the Senate in February 2020 in Washington.
CNN  — 

Sen. Susan Collins declined last week to back President Donald Trump for reelection, saying she would focus on her own race while suggesting that she only picked sides in 2016 because she was not on the ballot.

“I was not up for reelection,” the Maine Republican told reporters, referring to the 2016 race, when she publicly voiced her opposition to Trump’s presidential campaign. “I didn’t have my own race to worry about at that point.”

But a dozen years ago, as she was running for reelection, Collins endorsed Republican Sen. John McCain over then-Sen. Barack Obama. She served as a co-chairwoman for the McCain campaign in Maine and said she would be “glad” to have her friend campaign for her. At a debate in her 2008 Senate race, she argued that it was “typical for the leading officeholders to chair the campaign of whichever member of your party is running for President.”

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Asked Tuesday to explain the discrepancy between her position then and her refusal to say if she’ll endorse Trump now, Collins noted her “difficult race” against state House Speaker Sara Gideon and that she and the late senator had a close relationship.

“As I said, I have a difficult race,” Collins told CNN. “And I am concentrating my efforts on that race.”

“In addition, I have known John McCain since the 1970s, when I worked for Bill Cohen,” she said, referring to when she was an aide to the former Maine senator and McCain served as the Navy liaison to the Senate

“We were very close friends,” Collins added of her and McCain.

The contrast reveals the awkward spot Trump has left the senior Maine senator as she battles through one of the toughest elections of her 24-year Senate career. Serving in a Democratic-leaning state with many Trump supporters, Collins is seeking to avoid offending the GOP base while also appealing to swing voters put off by the President. In March, she refused to say how she voted in the Maine GOP presidential primary.

Speaking to reporters last week, Collins noted how Trump divides the state, saying that “in parts of the state President Trump is very popular, in parts of the state he’s very unpopular.”

“But I am running my own race,” she said. “I’ve always run my own race.”

The Collins campaign declined to comment.

In 2008, Collins ran for reelection with McCain at the top of the GOP ticket.

But even though McCain received only 40% of the vote in the state against Obama, she had perhaps less to fear then than she does now. The country was less polarized, her party was less beholden to its leader and her brand of political moderation and independence endeared her to her state. In 2008, a bad year for Republicans, she won with over 60% of the vote.

While the vast majority of Republicans in Congress have decided to endorse Trump, Collins has not. They have a complicated relationship.

In 2015, she endorsed former Florida Gov. Jeb Bush, whose family has a summer home in Kennebunkport, Maine. After Trump became the party’s nominee, Collins said she would not vote for him, writing in The Washington Post that Trump is “unworthy of being our president” and “does not reflect historical Republican values nor the inclusive approach to governing that is critical to healing the divisions in our country.” In 2016, she told CNN that Trump “would make a perilous world even more dangerous.”

The 2016 election marked not only a new kind of Republican party, but also cemented how congressional races have become increasingly aligned with the outcomes of the presidential contest, as the country becomes even more divided. That election year was the first in which every state voted for the same party in both the presidential and Senate races.

For Collins, that could be trouble. After Trump’s election, Collins opposed the Republican bill to repeal the Affordable Care Act and some nominees, including Education Secretary Betsy DeVos and some judicial picks. But she supported the party’s other top priorities, including the GOP’s tax overhaul bill, the confirmations of Supreme Court Justices Neil Gorsuch and Brett Kavanaugh and the acquittal of Trump’s impeachment. Amid the coronavirus pandemic, she has campaigned on her work helping pass the massive recovery packages providing relief to small businesses.

While that type of voting record might have once been rewarded in Maine, Collins’ popularity has suffered during the Trump era. The last New England Republican in Congress now faces her toughest reelection race. Gideon has outraised Collins by roughly $10 million, according to the latest FEC filings.