Barack Obama may be learning the limits of celebrity endorsements: It’s a big matter of debate if they can help you, but there’s little doubt that they can hurt you.

The Human Rights Campaign is stepping into the fray over Obama’s plans for a campaign event with Donnie McClurkin.

According to The Hill, the gay rights group has called on Obama to cancel the event or they will make a public pronouncement that he do so.

From The Hill, “Obama will not be present on the so-called Embrace the Change Tour, but public denouncement by the Human Rights Campaign could damage him in his quest for the White House.”

Blogger John Aravosis of AMERICAblog had this to say: “Funny how Obama is a big supporter of civil rights when blacks are being maligned, but not so much when gays are the victims. I really like Obama. I’m from Illinois. But this is despicable.” Earl Ofari Hutchinson called it the “gay bash tour.”

Obama issued a statement on Monday in which he repudiated homophobic comments — which is fine. Most commentators are giving Obama the benefit of the doubt, and haven’t said that this means he is homophobic. Nor do I. (The same goes for Hillary Clinton, John Edwards, Bill Richardson ….)

But Obama never addressed Hutchinson’s central request, that he drop McClurkin from the tour.   Did Obama seriously believe that his statement itself would end this debate?

Instead, this issue has festered, much like many of the other controversies we’ve seen this year, such as Don Imus. Unlike McClurkin, Imus apologized for his comments, but he still was fired.

The campaign certainly could be forgiven for not knowing about McClurkin’s comments — he was not that well known, and campaigns are certainly not the best at vetting. But when Hutchinson pointed it out they could have just admitted as such as and canceled plans. Instead, in campaign speak, this is a one day story that has been allowed to drag into a third day. And as the clock ticks, more people are hearing about it, more groups are chiming in and the more it hurts Obama’s support.

McClurkin gave an interview to the Chicago Tribune on Tuesday:

Writes Kelley L. Carter: “McClurkin told The Associated Press on Monday that “sexuality, everything is a matter of choice.” But on Tuesday he told the Tribune that his ideals, and most importantly his ministry, were severely misconstrued.

“I don’t believe that even from a religious point of view that Jesus ever discriminated toward anyone, nor do I,” McClurkin said in an exclusive interview with the Tribune. “Most of the things that were said were totally out of context and then other things weren’t true.”

“My only concern is to be in place with Sen. Obama in unity and bring all the factors together for the sake of change,” he said. “That’s my only thing. Of course some agents have twisted it as though he [Obama] were embracing a racist or a Nazi, and that is anything but true.”

Obama and McClurkin first connected at Oprah Winfrey’s fund-raiser last month.