Sen. Jeff Flake, R-Ariz., thinks more members of the Republican Party should have stood up to President Trump years ago, beginning with his support for the birther movement as not appropriate for conservatives to embrace.

"I wish we as a party had stood up, for example, when the birtherism thing was going on," Flake said on NBC's "Meet the Press."

"People did stand up, but not enough," he said. The birther movement challenged former President Barack Obama's right to be president by falsely claiming that he was not a U.S. citizen.

Flake, who is up for re-election in 2018, said he felt he did enough to stand up to the birther rhetoric, but would have liked to have seen more from his colleagues and others.