(CNN) President Donald Trump has boldly declared that he is a genius -- a "very stable" one at that. His Republican colleagues on Capitol Hill were not so quick to agree.

"He's smart and capable at getting himself elected president," said Kansas Sen. Jerry Moran.

But is he a genius?

Moran paused for several seconds, smiled and said simply, "Got nothing."

Moran isn't the only Republican to hesitate. In interviews with more than a dozen House and Senate Republicans on Monday, none of them agreed with Trump's assertion that his intellect is far superior than his peers'.

While they disagreed with the Democratic attack that Trump is not fit to be commander in chief, Republicans mostly laughed off Trump's repeated assertions that he's a genius -- even if the President himself seems to be serious about it.

"Listen, my view of the President -- I find him to be engaging, gracious, you know, pretty funny, and I don't have a question he's fit for office," said Sen. Ron Johnson, the conservative from Wisconsin.

Asked if he agreed with Trump's assessment that he's a genius, Johnson laughed, walked into the Senate chamber and didn't reply.

Trump over the weekend fueled debate over his intelligence after pushing back on Michael Wolff's book, "Fire and Fury: Inside the Trump White House," which questions whether he has the mental stability to hold office. As GOP leaders were huddled in Camp David for strategy sessions, Trump fired off a furious round of tweets attacking detractors for questioning his mental capacity.

"Actually, throughout my life, my two greatest assets have been mental stability and being, like, really smart," Trump tweeted. He added: "I went from VERY successful businessman, to top T.V. Star to President of the United States (on my first try). I think that would qualify as not smart, but genius....and a very stable genius at that!"

Asked if he agreed with Trump, South Carolina Sen. Tim Scott: "I'm not commenting on anything." Asked why not, Scott quipped: "I don't want to."

Neither did Sen. John Thune, the No. 3 Republican in the chamber.

"He obviously was just responding to the book, and I think he's just egging you guys on," Thune said.

But asked if he thought Trump was a genius, as the President often declares, Thune grinned and slipped into the ornate Inner Sanctum room on the first floor of the Senate without saying anything else.

Trump's weekend tweets are hardly the only time the President has boasted about his intelligence. He frequently says he has a very high IQ, pointing to his Ivy League pedigree and his successful real estate career. And he called himself a genius more than once.

"I don't really know what that means," said Texas GOP Rep. Roger Williams. "I mean the fact of the matter is that he was very successful in business, been elected President of the United States, excuse me that's a lot of success but the word genius?"

"There are not many geniuses, depending on how you describe them," added Sen. Richard Shelby, the senior Alabama senator, who also said Trump was "well and alert" when he spent time with him over the fall.

"No comment," said Sen. Jeff Flake, the Arizona Republican and frequent Trump critic.

Rep. Carlos Curbelo, a Florida Republican who declined to endorse Trump in 2016, was more blunt.

"I would never call myself that," Curbelo said. "It's not my style. But you know these characteristics that people were complaining about and some of the President's antics -- it's not new."

Sen. Bill Cassidy, a conservative from Louisiana, praised Trump's economic record and said, "I wish he would tweet less, but that's his style."

Asked if he agreed with Trump's tweet asserting that he's a genius, Cassidy said: "Well, again how many of us are geniuses in everything? But he's got great kids. Everybody in this accepts that he's got great kids."