Top WH official claims 'very real possibility' Ted Cruz loses to Beto O'Rourke. Cruz hits back hard.

A top White House official expressed concern behind close doors over the weekend that Texas Sen. Ted Cruz (R) is too vulnerable for comfort and risks being unseated by Democratic challenger Rep. Beto O'Rourke.

What are the details?

Mike Mulvaney, director of the Office of Management and Budget, told Republican Party donors at a closed-door meeting that the GOP is battling serious vulnerabilities ahead of the midterm elections, including widespread "hate" for President Donald Trump and the prospect that Cruz could lose for not being "likable" enough.

"There’s a very real possibility we will win a race for Senate in Florida and lose a race in Texas for Senate, OK? I don’t think it’s likely, but it’s a possibility. How likable is a candidate? That still counts," Mulvaney said, according to the New York Times.

The Washington Post separately confirmed Mulvaney's comments, reporting the wider context.

"Do people like you? It’s a really important question. It’s a very important question," Mulvaney said. "When you’re voting for your member of Congress, you want to have looked that person in the eye and decide whether you like that person or not."

Mulvaney made his comments alongside Republican National Committee chairwoman Ronna McDaniel. The pair reportedly reassured donors that Republicans would ultimately fend off Democrats' promised "blue wave."

Despite concerns that Cruz may be vulnerable, he still holds a respectable lead over his opponent. According to RealClearPolitics, Cruz averages a 4.4 percentage lead over O'Rourke in major polls.

How did Cruz respond?

The Texas senator, who was campaigning in Houston on Saturday, dismissed Mulvaney and his comments.

"I don’t worry about what some political guy in Washington says. I worry about what the people of Texas say," Cruz said.