Republican Rep. Will Hurd of Texas wouldn't say Thursday whether he'll support President Trump's re-election bid in 2020.

"2020 is a really long ways away," Hurd told MSNBC.

When asked if whether a question of backing Trump's re-nomination is one that should elicit a "simple yes" from a Republican member of Congress, Hurd deferred.

"Maybe it should, maybe it shouldn't," he said. "It's hard for me to ever think past the next election, and the next election I'm worried about is my re-election in 2018."

Since he assumed the presidency, Trump has struggled to unify the Republican party and he's often taken to Twitter to criticize many GOP lawmakers, including Senate Majority Leader Mitch McConnell, Sen. Jeff Flake of Arizona, and Sen. Lisa Murkowski of Alaska, among others.

Republicans haven't held back in condemning the president over his response to the violence in Charlottesville, Va., after Trump failed to immediately denounce the white nationalist groups involved in the rally there that ended with three dead.

Though the president eventually criticized the KKK, neo-Nazis, and white supremacists who protested in Charlottesville, he quickly reverted to his original statements that "many sides" were to blame for the violence there.

The president's frequent spats with GOP lawmakers have raised questions as to whether Trump will garner their support during his re-election bid.

In an interview with MSNBC on Monday, Sen. Susan Collins, R-Maine, also cast doubt on whether Trump will win the GOP nomination again.

"It's too early to tell now," she said. "There is a long ways between now and that point."

It's been more than 40 years since a sitting president had a serious primary challenger. In 1976, Ronald Reagan challenged then-President Gerald Ford, who ultimately won the Republican nomination.