DENVER — Minutes after President Obama endorsed gay marriage on May 9, Colorado's Democratic governor choked back tears as he ordered state lawmakers to reconsider a civil-unions measure defeated the day before by Republicans.
In the week that followed, the debate over equal rights for same-sex couples consumed the Capitol. Republicans succeeded in killing the measure, but lawmakers from both parties say the issue could play an important role in the White House race in Colorado.
"Go back to your communities, go back to your neighborhoods, go back to your churches and let them know that the fight continues," Republican House Speaker Frank McNulty told gay-marriage opponents gathered outside the Capitol on Tuesday.
Colorado Democrats predict that their loyalists, as well as independents, will rally behind Mr. Obama, given his support of same-sex marriage.
"That will have a positive impact on the chances of the president being re-elected and winning Colorado in November," said Democratic Rep. Mark Ferrandino, a gay lawmaker who co-sponsored the civil unions legislation and said that its supporters would be "very active" in the fall on the issue.
Mr. Obama plans to give the commencement address Wednesday at the U.S. Air Force Academy in Colorado Springs, before attending fundraisers in Denver.
Since 2008, equal rights for same-sex couples either through civil unions or gay marriage has flared in a few of the most contested presidential states. Two of those, Iowa and New Hampshire, now recognize gay marriage. North Carolina recently took the opposite stance, voting to strengthen its ban against gay marriage.
But the fight in Colorado has proved especially bitter, and feelings on both sides are raw. So Republicans and Democrats are bracing for social issues such as gay marriage and civil unions to factor into voters' calculations about whether to back the Democratic incumbent or likely GOP nominee Mitt Romney, who opposes allowing gay people to get married.
The economy is certain to dominate the race in the state. Colorado's unemployment rate is 7.9 percent, lower than in some swing states and marginally lower than the national average of 8.1 percent. But with joblessness falling, social issues could well become more of an issue in voters' minds.
Colorado has nine electoral votes, and the state is evenly divided among registered Republicans, Democrats and independents.
Just six years ago, Coloradans overwhelmingly voted to change the state constitution to ban gay marriage after a campaign largely funded by Focus on the Family, a conservative group based in Colorado that's influential across the nation.
By this spring, though, there was enough bipartisan support in the state Legislature to approve civil unions. Yet GOP leaders twice used legislative maneuvers to stop same-sex recognition, most recently last week.