WASHINGTON — Sen. Ted Cruz is warning that President Donald Trump making a deal with Democrats on gun legislation might cause conservative voters to stay home in 2020.

“If Republicans abandon the Second Amendment and demoralize millions of Americans who care deeply about Second Amendment rights,” the Texas Republican said, “that could go a long way to electing a President Elizabeth Warren.

“We’re going to see record-setting Democratic turnout. The only element missing is demoralizing conservatives so they stay home. I hope we don’t do that,” Cruz told reporters at a Thursday breakfast.

He was responding to a question that specifically referenced a possible deal between the Trump administration and a bipartisan group of senators including Democrats Christopher S. Murphy of Connecticut and Joe Manchin III of West Virginia, as well as Republican Patrick J. Toomey of Pennsylvania.

Those senators spoke with Trump on Wednesday and signaled that the president was nearing an announcement of his position on background checks for gun purchases.

“It would also be a serious mistake as a policy matter,” Cruz said, arguing that none of the recent mass shootings would have been stopped by the Democratic legislative proposals. He instead was pushing legislation he has drafted with former Judiciary Chairman Charles E. Grassley of Iowa that is focused on ensuring that federal agencies report all crimes into the existing background check database.

“The far left is pissed off,” Cruz told reporters Thursday. “They hate the president, and that is a powerful motivator.”

Cruz cited his own 2018 re-election contest against then-Rep. Beto O’Rourke, which saw record-setting Democratic turnout in Texas.

“The Texas Senate race ended up being the most expensive Senate race in U.S. history, and I think that foreshadows what 2020 will be nationally,” Cruz said.

Texas Republicans were able to get out the vote statewide and reelect Cruz, even as Democrats were picking up suburban House districts across the state.

Cruz said a move by the Senate GOP and the president to embrace the kind of gun bills already passed by the Democratic-led House or being promoted by the Democratic senators that have been working with Trump’s administration risks “demoralizing conservatives so they stay home.”

He said he thought Trump would carry Texas in 2020, and that incumbent GOP Sen. John Cornyn will win another term, but both contests will be real races.

Cruz did not entirely attribute the so-called “Texodus” of retiring House Republicans from the Lone Star state to changing demographics.

“Some of the retirements are simply House members who have been there a long time, and they’re ready to step down,” Cruz said, noting that life in the minority in the House is not particularly exciting.

“I think they’re enjoying it a lot less right now,” he said. “I can understand why for a Republican House member that’s less than enjoyable, to serve in a body that every day is obsessed with attacking the president.”

Cruz was speaking at a breakfast in Washington hosted by the Christian Science Monitor on the same day that the top Democratic presidential hopefuls were gathering in his home city of Houston for a primary debate.