Arlington County Board members say they are reconsidering their support of fellow member Christian Dorsey, because residents are objecting to his failure to return a $10,000 campaign donation as he promised.

The board is considering a range of actions, such as sanctions — including removing Dorsey (D) from his appointed position on the Northern Virginia Transportation Commission — and a letter to the public.

“We’re trying to figure out how to handle it in this social media world and to think about it in a responsible way,” said Libby Garvey (D), board chair.

Dorsey, who was reelected to his second term in November, resigned from the Metro board on Feb. 6 after that board’s executive committee planned to consider whether to reprimand or remove him from the unpaid position.

He was appointed to the board as Virginia’s voting representative 18 months earlier, after serving as Arlington County’s appointee for the previous 2½ years.

In his county board reelection campaign last summer, Dorsey accepted a $10,000 donation from the union that represents most of Metro’s workers and failed to disclose it to Metro, as the mass-transit agency’s ethics rules require, for four months. (It was properly disclosed in state campaign finance reports.) When he did disclose it to Metro, he promised to return the money to the union.

But his campaign account did not have enough cash left to do that, and Dorsey is going through a personal bankruptcy that has left him unable to pay it back himself. He said he still plans to repay the money, although he has no obligation to do so now that he no longer is on the Metro board.

The county board has already sent a letter to 17 residents who have written to members about Dorsey. The letter, signed by Garvey, said the board is “considering what, if any, are the next appropriate steps to take. We are very disappointed in Mr. Dorsey’s lack of judgment in accepting the donation, failing to report it in a timely manner, and not returning it in a timely manner.” The news outlet ­ARLnow first reported on the letter Thursday.

Garvey said the board has never imposed sanctions on anyone. She said she is trying to determine whether what Dorsey has done has caused harm to the county.

“There’s a danger to perceptions of the county, and that’s very real,” she said Friday.

Dorsey declined to comment beyond reiterating his intention to return the money.

Erik Gutshall (D), the county board’s vice chair, said the situation has been the talk of the county since The Washington Post reported that Dorsey had not repaid the donation.

“The answers we’ve gotten from Christian so far fall a little short and don’t seem to add up,” Gutshall said. “When you look at the whole picture, there’s been an apparent lack of candor. The risk for the board here is if it in any way undermines our ability to move forward on any actions, it’s a detriment to the board as a whole.”

Gutshall, who campaigned on a theme of trust in government, said, “I know Christian did not set out to create any strife, but here we are.”

Dorsey, who is well liked by colleagues, has until now enjoyed unrestrained support from the board. In January, Garvey said at a public meeting: “We are lucky here in Arlington, the region is lucky, and the state is lucky that we have Mr. Dorsey on the ­WMATA board. He is an excellent board member and provides outstanding service at no small cost to himself. We really appreciate his work.”

She said Friday that she stands by that statement.