Host Chris Matthews asked if he was advocating violence against an elected government. Barber said it was meant as a metaphor — "gather our political army." Matthews noted that wasn't what the ad actually says and Barber grew agitated. "Chris, do you know what a metaphor is?" he asked.

Moments later Matthews asked Barber if he'd ever been audited (the ad mentions "malicious audits" as a reason for rebellion). "It's irrelevant, I've been audited once," Barber said.

The ad prompted mixed feelings in Alabama Republicans.

"I think it's a very different way of looking at things," said Montgomery County GOP Chairwoman Pat Wilson. "I think people misunderstand it." She hadn't seen the Web ad, but speculated that was because it's directed at a younger, Web-savvy audience.

Barber said he'd received an overwhelmingly positive response from the district to his ads.

"People are frustrated with what's going on in the government, and they're willing to speak out about it," he said. "It's a bit on the controversial side, but most people resonate with the overall message."

A Roby campaign official said that Barber was pursuing a strategy of national attention and only represented a small number of people in the district.

Roby, backed by the National Republican Congressional Committee, is favored to clinch the nod in the July 13 runoff after taking first place in June primary. The winner faces Rep. Bobby Bright (D-Ala.) in November.

The two Republicans will meet again on Thursday in a debate co-hosted by the Montgomery County Republicans, two other northern counties and several Tea Party groups.