DENVER » A Colo­rado congressman who questioned the citizenship of President Barack Obama expanded on his apology Thursday, calling his comments at a GOP fundraiser this month "inappropriate and boneheaded."

Rep. Mike Coffman said in an op-ed column published Thursday in the Denver Post that he "should never have questioned the president’s devotion to our country. The president and I disagree on many issues — his approach to health care, jobs and energy independence, to name a few. But disagreeing on these issues was not license for me to question his devotion to our country."

Earlier this month the Republican congressman said at an Elbert County event that he doesn’t know whether Obama was born in the United States and that in his heart, Obama is not an American.

Coffman’s remarks echoed a long-simmering political controversy generated by those who say that Obama was born abroad and is ineligible to hold the nation’s highest office. The Obama administration moved a year ago to dismiss the conflict by releasing his long-form birth certificate showing that he was born in Hawaii.

Coffman faced intense criticism after a recording of his comments was released to the media. He released a short statement apologizing for the remark before he wrote the newspaper column.

It’s too soon to say what the long "mea culpa" from the two-term congressman will mean for his re-election bid in a suburban Denver district that has become much more competitive for Demo­crats because of redistricting. Coffman rolled up big wins in his first two contests for the district, carrying roughly two-thirds of the vote against a little-known Demo­crat with no political experience two years ago.

But Coffman faces a dramatically different landscape this year because of congressional redistricting. Coffman’s turf now is divided roughly evenly among Democrats, Republicans and independents. Colo­rado’s 6th Congressional District will soon include the entire city of Aurora, a one-time Republican stronghold trending toward Demo­crats.

Coffman will no longer represent the most conservative parts of his current district, including Elbert County.

In the op-ed, the congressman called questions about Obama’s citizenship a "distraction."

"I have never been afraid to admit when I am wrong, and I was wrong here," Coffman wrote.

Democrats have seized on Coffman’s remark as evidence he’s too conservative for the district. Coffman’s Demo­cratic challenger, state Rep. Joe Miklosi, called it "a comment you would normally hear from Rush Limbaugh."

Questions about Obama’s citizenship persist among some skeptics, though Hawaii officials have repeatedly verified Obama’s birth rec­ords. Also, GOP leadership and presumptive Republican presidential nominee Mitt Romney have denounced such doubts. And state and federal courts also have rejected lawsuits over the issue.