"It's looking for its relevance in all of the wrong places. There used to be a war. And we won that war on civil rights. Are there some battles? Yes, there will always be. I believe that their new focus should be economic development, but they have not made that transition, so they have simply lost their relevance," Cain said on "Fox and Friends."
"There's a double standard, just like there was a double standard all the way back when President Obama was Candidate Obama … because many people in that audience are liberal-thinking and they are basically overlooking the failure of this president and this administration," Cain said.
Romney was booed during his remarks at the convention when he vowed to repeal Obama's signature healthcare
law, as well as at other points in his speech.
Vice President Biden addressed the group Thursday on behalf of the White House, where he defended the healthcare legislation and suggested Romney and Republicans would work against the organization on issues ranging from voter rights to racial profiling.
Cain lamented the media coverage of Romney's speech at the NAACP, saying there was too much focus on the booing and not enough on the applause that Romney received from the crowd.
He pointed out that he heard applause when Romney discussed how he would revive the economy and cut spending, but predictably elicited a negative reaction when he used "trigger words" like "repeal ObamaCare."
The former GOP presidential hopeful also accused Obama of playing the "race card" and the "class warfare card" in his campaign.
"I believe that the Democrats and the Obama administration, they are in fact going to make this very racial this time around," Cain said.