Rep. Justin Amash's Republican primary challenger is out with a new TV ad hitting him for being too soft on national security.

"It makes no sense. You know, we were out there fighting for the country and he's voting against anything that would help us," says the man, identified as former Marine Ben Thomas. The ad is from the campaign of investment manager Brian Ellis.

Amash, of Michigan, is a libertarian-leaning Republican with a loyal tea party following. He's clashed with business leaders, many of whom prefer Ellis.

Thomas says in the commercial that he concurs with Rep. Devin Nunes (R-Calif.), who called Amash "al-Qaeda’s best friend in the Congress" in an interview with Politico. Nunes has helped Ellis raise money.

"Mr. Amash, you were called al-Qaeda's best friend in Congress -- and for good reason," Thomas says. "Your votes put America at risk. And that's a disgrace."

In a statement responding to Ellis's ad, Amash insisted that members of the military do not support broad surveillance on everyday citizens or wars without an end.

"Our brave men and women in uniform don't support unconstitutional NSA spying on ordinary Americans -- which Ellis specifically endorses in his ad," he said. "They don't support unwise, open-ended wars. As I've heard from hundreds of veterans in my district, they want what I consistently vote for: a well-equipped and well-trained Armed Forces that honors its commitment to veterans and a government that protects our rights."

A recent automated poll showed Amash leading Ellis by 20 points.