Clinton said the former first lady, who died on Sunday, "started a national conversation" on AIDS that "penetrated the public conscience and people began to say, 'Hey, we have to do something about this, too,'" during an interview with the network at Reagan's funeral.
But Nancy Reagan's husband, President Ronald Reagan, didn't deliver a major speech on the epidemic
until 1987, six years after the Centers for Disease Control and Prevention first reported on the disease
. Many in the gay community have criticized Reagan for not doing more to respond to the AIDS outbreak during his presidency.
Chad Griffin, the president of the Human Rights Campaign and a former Clinton White House aide, knocked the Clinton on Friday for incorrectly holding Reagan up as an activist.
Clinton soon after tweeted an apology.
"While the Reagans were strong advocates for stem cell research and finding a cure for Alzheimer's disease, I misspoke about their record on HIV and AIDS," Clinton said in a statement. "For that, I'm sorry."
Griffin's shot at Clinton is noteworthy given the gay rights activist's ties to the Democratic family. He campaigned with Clinton in Iowa in January.
In the MSNBC interview Clinton, unprompted, heralded Reagan's activism.
"The other point to make, too, is it may be hard for your viewers to remember how difficult it was for people to talk about HIV/AIDS back in the 1980s," Clinton said. "And because of both President and Mrs. Reagan, in particular Mrs. Reagan, we started a national conversation, when before nobody would talk about it."
Clinton added: "Nobody wanted to do anything about it. And, you know, that too is something that I really appreciate with her very effective low-key advocacy, but it penetrated the public conscience and people began to say, hey, we have to do something about this, too."