(Jim Cole/AP Photo)

Rep. Ron Paul’s non-interventionist foreign policy came under fire Friday at a campaign stop in New Hampshire, where many of his views were met with open grumbling from the audience.

He has called for the United States to withdraw from all foreign wars and has also suggested that most U.S. military bases overseas be closed, calling the price tag “unsustainable.”

Paul’s view that a withdrawal of U.S. troops would decrease the incentive for terrorists to attack the United States had one woman at an assisted living center in Concord question his sanity.

“If we bring all the troops home some people think the terrorists will say, ‘America isn’t so bad after all and we are not going to try to kill civilians anyone,’” one woman said. “Anyone who thinks that is off his rocker.”

Paul paused, took a few steps back, and said that his view was that of the 9/11 commission whose task it was to investigate the causes of the terror attacks of Sept. 11, 2001.

“All empires end and we are an Empire,” he told her.

Rick Santorum has also challenged Paul to explain his view that American overseas domination caused the Sept. 11 attacks.

During the Republican CNN/Tea Party debate in early September, Paul’s answer received a hostile response from the audience and a few even booed the Texas congressman.

At the campaign stop in Concord Friday, one man asked Paul to cite an example of an empire that voluntary relinquished power.

Paul, seemingly again taken off -guard, did not immediately answer, but then cited Cicero, a Roman senator who tried to preserve the Roman republic only to fail and was eventually killed.

“There is no president, ” the man fired back.

But not everyone in the audience seemed told Paul’s foreign policy views against him.

During a pause between questions, one elderly man blurted out, “Don’t buy a foreign car.”

“I drive a Ford,” Paul said.

The elderly man shot back, “Good, I’ll vote for you.”