Sen. Susan Collins of Maine has been under fire from both Democrats and fellow Republicans during the Trump era. Democrats are angry that the 66-year-old senator has been voting with President Donald Trump too often, while the far right has been insisting that she isn’t pro-Trump enough. And Collins is considering not seeking reelection in 2020, Bloomberg News is reporting.

Collins, according to Bloomberg’s Steven T. Dennis, won’t decide for sure whether or not she will seek a fifth term until the fall. And a major problem is the fact that her approval ratings have been plummeting: according to Morning Consult, Collins’ approval in Maine has gone from 78 percent in 2015 to a mere 45 percent in 2019.

Potential 2020 challengers for Collins — assuming she does decide to seek another term — have been lining up on both the Democratic and Republican sides.

Right-wing blogger Derek Levasseur, earlier this year, announced a GOP primary challenge to Collins in Maine. As Levasseur sees it, the conservative-leaning Collins isn’t conservative enough. If Levasseur were to defeat Collins in the primary, she wouldn’t even make it to the general election. And if she defeated Levasseur and did reach the general election, she could face an equally fired up Democrat.

It remains to be seen who that Democratic challenger would be, but Maine Democrats have been lining up for an opportunity to take her on in the general election. And they range from Sara Gideon (speaker of the Maine House of Representatives) to attorney Bre Kidman to retired U.S. Air Force Gen. Jonathan Treacy.

To say that the Democratic National Committee (DNC) is longing to see Collins’ seat in Democratic hands in 2021 is an understatement. If Democrats can maintain every Senate seat they are defending in 2020 and take four seats from Republicans, they would achieve a Senate majority — and the DNC sees Collins as quite vulnerable.

The Trump era, as Dennis notes in Bloomberg, has “been hard on Collins.” Democrats are furious with her for various reasons — namely, her vote to confirm Justice Brett Kavanaugh to the U.S. Supreme Court in 2018, although her vote in favor of the GOP-sponsored Tax Cuts and Jobs Act angers them as well.

But on the Republican side, Collins is routinely lambasted for being pro-choice on the abortion issue and for opposing GOP efforts to repeal the Affordable Care Act of 2010, also known as Obamacare.

In an interview with Bloomberg News, Collins expressed her dismay over the angry partisan divisions in the U.S. yet seemed optimistic about her ability to overcome her low approval ratings — asserting, “The divisiveness of our country and the unceasing attacks by dark money groups in Maine have clearly had an impact. But I believe that once Mainers really focus on the race and we remind them of my being the No. 1 most bipartisan member of the Senate — and all the accomplishments that I can point to that have directly benefited the state — I’ll be fine.”