Sen Ted Cruz (R-Texas) has a warning for his fellow Republicans: The party is in danger of losing both houses of Congress in November.

Cruz said the “extreme left” could turn out in big numbers, motivated to fight the agenda of President Donald Trump.

“We know that the left is going to show up,” Cruz told conservative radio host Hugh Hewitt. “The extreme left, they’re angry. They’re filled with rage. They hate the president.”

Cruz also said that if the economy is booming and conservatives show up at the polls, his party could pick up as many as seven seats in the Senate and hold a “large, functioning majority.”

However, he also warned of the opposite scenario:

“If conservatives are complacent, and mark my words, we are going to see historic turnout from the extreme left in November, which means if conservatives stay home, we have the potential, we could lose both houses of Congress.”

If Democrats take control of the House, he predicted that Rep. Nancy Pelosi (D-Calif.) would become speaker again and immediately initiate impeachment proceedings against Trump.

Closer to home, Cruz also warned of a possible blue wave in the Lone Star State.

“In Texas, if conservatives stay home, if we rest on our laurels, we could see Texas turn blue,” he said. “We could see every statewide official in the state becoming a Democrat.”

He added that he didn’t think that was likely.

Democrats are facing a daunting Senate map this November, defending more seats than Republicans, including several in states that voted for Trump in 2016, such as Florida, Indiana, Missouri, Ohio, North Dakota and West Virginia.

Cruz himself is up for re-election. While his seat is considered safe, he’s facing a challenge from Rep. Beto O’Rourke, a Democrat from the El Paso area.

O’Rourke raised $2.3 million in the first six weeks of 2018, or nearly triple the $800,000 raised by Cruz over that period, according to the Texas Tribune.

Story continues

While O’Rourke is still considered a long shot, the Cook Political Report changed Cruz’s seat from “Solid R” to a “Likely R” earlier this year.

Also on HuffPost

Love HuffPost? Become a founding member of HuffPost Plus today.

This article originally appeared on HuffPost.