Critics have suggested that Mr. Beck was trying to energize conservatives for the midterm elections in November. Mainstream Republican leaders remain skittish about the group emerging on their right — and the influence it displayed in primary elections Tuesday — and had little to say about the Beck event.

Image The rally was held at the site where the Rev. Dr. Martin Luther King Jr. delivered his “I Have a Dream” speech 47 years ago to the day. Credit... Chip Somodevilla/Getty Images

But in an interview aired Sunday, Mr. Beck denied any political motivation — or political aspiration — and shrugged off conservatives’ suggestions that his ability to mobilize so large a crowd made him presidential material.

“There’s nothing we can do that will solve the problems that we have and keep the peace unless we solve it through God,” he told “Fox News Sunday.”

He also expressed regret for having asserted last year that Mr. Obama was a racist with a “deep-seated hatred for white people,” a comment that many critics felt undercut Mr. Beck’s assertion of racial tolerance.

“It was poorly said — I have a big fat mouth sometimes,” Mr. Beck said.

He said he had come to see Mr. Obama not as a racist but as an advocate of “liberation theology,” which he said pitted victims against oppressors. Liberation theology has generally been used in reference to a movement, begun in the Roman Catholic Church in poor parts of Latin America in reaction to social injustice, that some critics say has been taken over by leftists.