WASHINGTON ― Sen. Jeff Flake (R-Ariz.) said Sunday that Republicans should have done more to push back on “birtherism,” the conspiracy theory that former President Barack Obama was not actually a U.S. citizen.

While he said he personally stood up to birthers, Flake told NBC’s “Meet the Press,” he wished the party would have done more during this “particularly ugly” time.

“I wish that we, as a party, would have stood up, for example, when the birtherism thing was going along,” he said. “A lot of people did stand up but not enough.”

Flake, who is promoting a book called Conscience of a Conservative, has been especially outspoken in recent days against President Donald Trump and has criticized his fellow Republicans for doing too little to prevent his rise.

But he has also repeatedly voted with Trump, who has promoted birtherism. In July he voted with other Senate Republicans to make John Bush, a man who published blog posts citing birther sources, a federal judge. (Bush denied being a birther during his confirmation process, telling senators that he was just repeating information on his blog for his readers.)

Flake told NBC that while he has voted with Trump most of the time, it was because the Senate’s role in the first months of any presidency is largely “the personnel business.”

“All we’re doing really is approving the president’s cabinet picks, justices,” Flake said.

He said he does expect to vote against Trump on some matters, such as trade.

Flake’s office did not immediately respond to a request for comment on his vote for Bush.

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