President Donald Trump is endorsing Sen. John Cornyn for re-election in 2020, saying the chamber's No. 2 Republican "has done an outstanding job for the people of Texas."

The president tweeted Thursday that Cornyn is "strong" on the Second Amendment, the U.S.-Mexico border and crime, and "loves" the military.

Trump added: "John has my complete and total endorsement." Cornyn isn't expected to have a close re-election fight.

Still, Trump's endorsement follows Cornyn sending out a fundraising email to supporters on Wednesday titled "Stop Beto," and suggesting that former Rep. Beto O'Rourke could challenge him.

O'Rourke nearly upset Sen. Ted Cruz in deeply conservative Texas in November and says he may run for Senate again — though most speculation has focused on him seeking the White House in 2020.