President Trump on Thursday warned that GOP Senate candidates who don’t fully embrace him will lose their elections, a warning shot to some moderates who have kept their distance from the president.

Trump called into Maria Bartiromo‘s show on Fox Business Network, where he predicted Republicans would take back control of the House despite little polling to support that argument. But he acknowledged it may be more difficult for the GOP to maintain its slim majority in the Senate.

“We’re fighting very hard in the Senate. I’ll be honest, the Senate is tough,” Trump said. “We have a couple of people that aren’t as supportive of Trump as they should be, and those people are going to lose their elections.”

Read more at The Hill.