Willie McMillan and Charlie Hudson are buddies, African American men who were thrilled beyond compare when they had the chance to help make Barack Obama the nation’s first black president. They both believe same-sex marriage is an affront against God, a sin that simply cannot be condoned. As of Wednesday evening, McMillan has switched sides and will vote for Mitt Romney for president, whereas Hudson is sticking with President Obama.

News that Obama had announced, after many months of hedging, that he supports same-sex marriage and believes it should be the law of the land was not exactly a shock; he had been signaling that he was moving in that direction — “evolving,” as he put it — for years.

But on street corners, in bars, coffee shops and sports clubs, voters gay and straight parsed the president’s words, and, although they differed on whether the announcement would help or hurt his reelection chances, most concluded that his decision was based on conscience rather than political calculus.

Obama had to be acting from his heart, McMillan and Hudson agreed, because they couldn’t see how his position could win him any political edge. But that's all they could agree on.

“I’m sorry, I was tickled and proud to see a black president, but I can’t vote for a man who goes against God,” said McMillan, 66, who lives in the Logan Circle area of Northwest. “I don’t believe in skin color more than I believe in God’s word. This president must be part atheist or something.”

“There’s more than one issue,” replied Hudson, 68. “This doesn’t make him a good or bad president; he just made a bad decision.”

A few blocks away, at bars on 17th Street NW that fly the rainbow flag as a symbol of gay pride, Obama’s decision was greeted as late but more than welcome.

“It’s about time somebody stood up for us,” said Jacqueline Ward, 29, who was having a drink with her partner. “There’s other issues that matter more — I mean, there’s still a war going on — but maybe he can push people to be more open-minded. He must really believe in it because it’s not going to win him a lot of votes.”

By November, will it matter whether voters believe the president acted out of political expediency or personal ethics?

“I don’t know what he believes,” said Cheryl Sanders, a pastor at the Third Street Church of God in the District’s Mount Vernon neighborhood and a professor of Christian ethics at Howard University’s divinity school. “But it’s okay to change your mind . . . and my sense is that he will probably gain more votes than lose votes.”

Sanders opposes same-sex marriage but says the president’s stance isn’t likely to diminish his support from black voters, just as his support for abortion rights hasn’t chased away blacks who oppose abortion on religious grounds.

“I don’t think it will work to wipe out all the other things: war, the economy, health care,” she said.

But some voters on both sides of the marriage debate were confounded by Obama’s statement, believing his new stance will cost him dearly.

“Political suicide,” Robert Fenton called it. A 29-year-old Navy veteran who supports gay marriage, Fenton said he had the impression that Obama “really always supported same-sex marriage. He just repressed it so he could become more mainstream” and appeal to independent voters.

Such gamesmanship has left Fenton, a Fairfax County resident and a doctoral student in sociology at George Mason University, disgusted with politics. When politicians hide their true views for years to appeal to the political center, “I don’t put any trust or faith or hope in the two-party system,” he said.

Like Fenton, Mike McManus thinks the president has “signed his death certificate.” Unlike Fenton, McManus thinks Obama is on the wrong side of the issue.

McManus, who runs a Christian counseling group in Potomac, doesn’t think Obama acted out of conscience, but rather because he was “outed” when Vice President Biden made his support for same-sex marriage plain last weekend.

“This is a religious country,” McManus said.

Still, he said, views are changing and even churches are reluctant to take a strong stand. He’s been gathering signatures to put a referendum on the Maryland ballot this fall to overturn the new law allowing same-sex marriage, and of the 10 churches he called Wednesday to ask if he could put petitions in their lobbies, eight declined, for fear of alienating divided members, he said.

Although marriage wasn’t a factor for African Americans in Obama’s first campaign, it could be this time, said William Cabell, 49, of Upper Marlboro. Obama’s new stance “threw me for a curve. I’m trying to figure out how I’m going to support him now, because I don’t have the same belief.”

Cabell, a black Democrat, knows he will vote against same-sex marriage in Maryland’s referendum but can’t see casting another ballot for Obama.

“I’d love to be supportive to my president,” said Cabell, who works for the Montgomery County school system. “I have to be loyal to my God.”

The Rev. Nathaniel Thomas, pastor of Forestville New Redeemer Baptist Church and a leader of the campaign against Maryland’s new marriage law, said Obama’s statement “took the wind out of me. His family image has been great for our community, and now he has allowed another agenda to cloud the great, positive image he created of the black family.”

Wenona Price, however, plans to stick with Obama, even though she will vote against same-sex marriage in Maryland.

“There are a lot of things that people might do that I don’t agree with, but it doesn’t mean that we end our relationship,” said Price, 49, an entrepreneur in Clinton. “You have to look at his work in the past four years. I think his pluses outweigh his minuses.”

Diana King, an 18-year-old Alexandrian who will vote for the first time this fall, disagrees intensely with Obama on the issue. “God didn’t make people like that,” she said. “He didn’t make two men to have babies together.”

But she intends to vote for him anyway; she remains moved by his personal story of being raised by a single mother to become the first African American president.

“He inspires me,” King said.

Staff writers Emma Brown, Hamil R. Harris and Ovetta Wiggins contributed to this report.