"The ObamaCare attractiveness and feature was something we underestimated particularly among lower incomes," he added. "We just didn't do as good a job at connecting with that audience as we should have."
Latino votes made up 10 percent of the electorate in November for the first time ever.
Romney won 27 percent of that vote to Obama's 71 percent. It was a poor performance compared to his Republican predecessors — exit polls show that former President George W. Bush won 44 percent of the Latino vote in 2004, and Sen. John McCain (R-Ariz.) won 31 percent in 2008.
Romney came under intense fire during the campaign for a private remark that "47 percent" of Americans "believe they are victims" and "believe the government has a responsibility to care for them."
On Sunday, he called it a "very unfortunate statement."
"It's not what I meant. I didn't express myself as I wished I would have," Romney said.