In this Jan. 26, 2021, file photo, U.S. Sen. Susan Collins, R-Maine, right, speaks to a reporter after leaving the Senate floor in Washington. Credit: Jacquelyn Martin / AP

U.S. Sen. Susan Collins on Wednesday defended her vote to convict Donald Trump in his second impeachment trial as she faces a potential censure later this month.

In a letter to the Maine Republican Party’s Executive Committee, Collins said she swore to perform “impartial justice” during the former president’s impeachment trial for his role in the deadly Capitol riot on Jan. 6.

“This is an oath I took very seriously, just as I did when I voted to acquit President Trump in the 2020 impeachment trial. The decisions I made in both trials were based on the Constitution and the evidence before me, not on my membership in a political party or any other external factor,” Collins said in the letter, released by her office late Wednesday night.

That came in response to a Wednesday letter signed by 38 Maine Republican Party officials who wrote that the party’s grassroots are “almost universally outraged” by the impeachment trial. Their letter made no mention of censure, and they thanked Collins for her support of the party, county committees and individual candidates.

Collins was one of seven senators to vote to convict Trump on Saturday when the impeachment trial concluded. It was the first time she voted to convict a president during an impeachment trial, voting to acquit Democratic President Bill Clinton in 1999 and Republican Trump in 2020.

Since then, Republicans who voted to convict have faced a backlash from state parties. Republicans in five state House districts in Alaska passed resolutions Wednesday censuring U.S. Sen. Lisa Murkowski for her vote and further action from the state party is expected, according to the Anchorage Daily News. That leaves just Utah U.S. Sen. Mitt Romney and Collins who have yet to be rebuked back at home.

The state party issued no statement after the senator’s vote, but Maine Republican Party Chair Demi Kouzounas told party members in a Saturday email that “many of you are upset after what happened today as are we” and “to be prepared for an emergency state committee meeting in the near future” to discuss the Collins matter.

A vote to censure Collins could come by the end of the month.

In her Wednesday letter, Collins did not directly criticize state party officials for their criticism of her vote or the moves toward censure. Instead, Collins urged the party to improve its electoral performance.

Collins noted that she won reelection to a historic fifth term last November while splitting the ticket with Maine’s presidential results, leaving her the only New England Republican to hold federal office.

“Unfortunately, the other races in Maine did not go as well. Democrats won in the presidential race and the two congressional races, and they maintained control of the State Senate and State House. Moreover, the Democrats continue to increase their substantial enrollment advantage over Republicans,” she said.

She called on Republicans to focus their attention on an upcoming special election for Maine Senate District 14 on March 9. That Augusta-area seat was left vacant when Democrat Shenna Bellows became Maine secretary of state. Republican William Guerrette and Democrat Craig Hickman are set to face off for it.

Collins called it a “very winnable” district, where she won by more than 3,700 votes in November 2020 while Trump lost it.

“I hope that we are able to work together to improve our electoral results. Now would be a good time for us to consider how we can improve our performance in the 2022 and 2024 cycles,” she said.