Former D.C. mayor Vincent Gray wipes his brow during a press conference in this 2012 file photo. (Daniel C. Britt/The Washington Post)

He’s free of his legal troubles, angry about how he was treated and eager to speak out on District issues. Many believe he’s preparing to run for the D.C. Council and stands a good chance of winning.

Former mayor Vincent C. Gray (D) is back in a big way and shows every sign of trying to reclaim his spot on center stage in city politics.

A Gray comeback poses a major challenge to Mayor Muriel E. Bowser (D), the woman who ousted Gray last year in what he says was a tainted election.

Bowser, in office almost a year, hasn’t faced much pushback as mayor in what might be called an Era of Good Feelings in District politics.

D.C. Council members have opposed Bowser on some issues, such as questionable fundraising and the proposed Pepco-Exelon merger. But there have been no major battles or personality clashes, and her approval rating is high.

Muriel Bowser, in office almost a year, hasn’t faced much pushback as mayor in what might be called an Era of Good Feelings in District politics. (Bill O'Leary/Washington Post)

The honeymoon could end following the announcement by U.S. prosecutors Dec. 9 that they would not charge Gray with crimes related to the illegal financing of his 2010 mayoral campaign.

In the aftermath, Gray confirmed he was considering running for a seat on the D.C. Council next year — a race that many D.C. politicians and insiders predict he would win and give him a platform to confront the mayor.

Gray also let loose on Bowser in media interviews Tuesday, faulting her for her ethics and handling of the Pepco-Exelon deal. His advisers said he was ready to attack her as well over poor handling of the city’s finances and this year’s surge in homicides.

“This is a man who does not shy away from criticizing government and elected officials when he feels they’re not doing their job properly,” Chuck Thies, Gray’s former campaign manager, said. “You have a mayor that is still just getting her feet wet, who was elected to office with questions about her capabilities, and she has a thin skin.”

The U.S. Attorney General's office announced Wednesday that it is ending its long-running investigation into former D.C. mayor Vincent Gray's 2010 campaign. (WUSA9)

Gray also doubled down in the interviews when he suggested that Bowser’s victory over him in the April 2014 primary was illegitimate. He said he would have won except for a controversial news conference three weeks earlier, in which then-U.S. Attorney Ronald C. Machen Jr. left the impression in many people’s minds that Gray would probably be indicted.

The former mayor used the loaded phrase “voter suppression” to describe the impact on his political base in less affluent, predominantly black neighborhoods in Wards 7, 8 and 5 in the eastern part of the city.

It is true that polls at the time showed Gray ahead of Bowser before the news conference, and she jumped ahead of him afterward. But the polls also indicated that more than half of voters distrusted Gray even before the news conference, and that opposition was beginning to coalesce around Bowser. Gray’s level of support among likely voters in the mayoral race did not drop following Machen’s comments, polls showed, but stayed about the same.

[Why it was Muriel Bowser, not Ron Machen, who beat Vince Gray.]

Either way, the end of the nearly five-year federal probe of Gray “creates a new dynamic for the political universe of the District of Columbia, and obviously lifts a cloud that had been hanging over Vince Gray’s electability,” D.C. Council Chairman Phil Mendelson (D) said.

Gray declined to be interviewed for this story. Thies, who is handling Gray’s media relations on a volunteer basis, said that Gray “is displeased with your coverage of his time as mayor and related subjects.”

Gray said Tuesday he was thinking of entering the Democratic primary in June to challenge Council member Vincent Orange for his at-large seat, or Council member Yvette M. Alexander for her seat representing Ward 7.

Gray would be a strong candidate, particularly in the race for Alexander’s seat, which Gray held from 2005 to 2007, political observers said. He would benefit from name recognition and a generally positive reputation, apart from the devastating scandal in which six people pleaded guilty to crimes directly related to more than $650,000 in illicit funds spent on Gray’s campaign.

The end of the federal investigation “gives Vincent’s supporters a chance to rally and get organized,” said William P. Lightfoot, a personal-injury lawyer who chaired Bowser’s mayoral campaign. He described Orange and Alexander as “vulnerable . . . especially to Vince,” and said Gray’s return to the Council was “probable.”

Council member Mary M. Cheh (D-Ward 3) welcomed that prospect, saying Gray “would be an excellent and strong member of the body.”

She predicted Gray would run and said that if he won, he would cost Bowser support on the council.

“If he runs for either of those seats, it would be one more in the loss column for a reliable vote for whatever she is doing,” Cheh said.

Gray would be especially outspoken, she added.

“Nobody thinks there’s love lost between Gray and Bowser. I suspect that he will be a critic of things he doesn’t like, and unabashedly so,” Cheh said.

In public, at least, Bowser and her advisers have played down any risk of a Gray revival.

Asked at a news conference Tuesday afternoon about Gray’s barbs delivered earlier in the day, Bowser said she hadn’t paid attention because she was busy preparing for the media event, which was about release of police body camera footage.

“At some point, you’ve just got to govern, and the politics will be what the politics will be,” said a Bowser adviser, who spoke on condition of anonymity because of the sensitivity of the issue.

When pressed about the possibility that Gray would continue his political attacks in a council run, the adviser started reeling off issues where the Bowser team thinks Gray is vulnerable.

Several major projects were stalled or poorly handled when Gray was in office, the Bowser adviser said, including the H Street corridor streetcar, the Skyland redevelopment project in Southeast, and the building of a new soccer stadium.

“If he’s going to run, I assume he’s going to run on his record, and I think that record is somewhat thin,” the adviser said.

Orange and a spokeswoman for Alexander declined to comment directly on the possibility that Gray might challenge one of them, saying they were busy doing their jobs.

“I’m not going to get caught up in hypotheticals,” Orange said. “I know I will be on the ballot and I will be victorious. . . . I’m slim and trim and ready to go.”

One potential roadblock for Gray is a lingering perception that his hands weren’t necessarily entirely clean in the campaign finance scandal. As is typical in such cases, the announcement by U.S. Attorney Channing D. Phillips didn’t explicitly say that Gray was innocent, but only that prosecutors had insufficient admissible evidence to charge him.

Perhaps more important, as Gray himself conceded in one interview, he was under some obligation to ensure that his 2010 campaign was honest.

“I take responsibility as a candidate, but in the end, you have to trust the people who are working on your behalf,” Gray told the New York Times.