(CNN) – In Donald Trump we don’t trust. A number of lawmakers on Capitol Hill refusing to say they have faith in a possible president Trump handling the nation’s nuclear codes, and that is coming from republicans!

As Donald Trump tries to sell voters on his national security credentials, some republicans in congress are struggling with a key question.

CNN’s Manu Raju: “Do you trust Trump having his finger on the nuclear button

Tennessee Senator, Lamar Alexander: “I support the republican nominees”

Raju: “What about the nuclear code can he be trusted on that?” asked Raju.

Sen. Alexander: “I support the republican nominees and I’m glad to do it.”

Raju: “Do you trust Donald Trump with his finger on the nuclear button?”

Sen. John Cornyn: “I think he’s a better choice than Mrs. Clinton, who’s proven herself time and time again to be untrustworthy. She can’t even speak truthfully about whether she’s telling the truth. And that troubles me terribly.”

Raju: “What about Trump?”

Sen. John Cornyn: “Well i think he’s a better choice.”

But the top republican in the senate has no doubts.

Raju: “Do you feel confident that he can be trusted with his finger on the nuclear button?”

Sen. Mitch McMonnell: “I didn’t hear the speech today but the answer’s yes.”

Polls paint a different picture, including a recent survey that found 54 percent of voters trust Clinton with the nuclear codes, compared to just 35 percent for Trump. Yet Clinton’s lead is just five points when voters are asked which candidate would be a better commander-in-chief.

Other republicans in tough races this November, like New Hampshire’s Kelly Ayotte and Arizona’s john McCain, also won’t answer directly.

Rep. Will Hurd said, “My race is about me.”

And neither will endanger house republicans.

Raju: “Are you comfortable with him having his finger on the nuclear button?”

Florida’s Rep. David Jolly: “I have yet to endorse him. I don’t anticipate getting there by November.”

Raju: “If he had his finger on the nuclear buttons would you be comfortable with that?”

Rep. David Jolly: “I have strong policy disagreements with Mr. Trump.”

The anxiety showing that Trump still has work to do to convince his own party he can lead the nation’s military. Today in Philadelphia, Trump painted Clinton as the one who is reckless.

“She’s trigger happy and very unstable”, remarked Trump.

And congressman Joe Heck, running to be Nevada’s next senator, isn’t dancing around the question.

Raju: “are you completely supporting him?”

Rep. Joe Heck: “I am.”

Raju: “do you trust him having his finger on the nuclear button?”

Rep. Joe Heck: “I do.”

Raju: “why do you say that?”

Rep. Joe Heck: “Why wouldn’t I?”