URBANDALE, Iowa – During remarks to supporters inside her campaign headquarters Saturday, Michele Bachmann linked President Barack Obama to a large protest that had been unfolding outside the building only minutes before.

"You may have seen all over Des Moines the Barack Obama re-election advance team is already out there in the various parking lots of all of the campaigns," Bachmann told about 70 volunteers.

"This tells you that he is nervous," she continued.  "He doesn't want me on the stage. I want you to know, I'm not nervous. I'm fearless."

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The rhetoric signifies a heightened effort to paint Obama as out of touch, something the campaign acknowledges is an element of Bachmann's closing argument to voters three days before the Jan. 3 caucuses.

About 100 protesters from anti-Wall Street "Occupy" groups around the country descended on Bachmann’s headquarters Saturday, prompting campaign staff to lock the front doors and block the entrance.

Police, stationed outside the building, arrested 10 people on trespassing charges.

The protesters called for "an end to corporate money in the political system," according to a press release sent Saturday morning. 

They also visited the campaign headquarters of Texas Gov. Rick Perry, former House Speaker Newt Gingrich, and former Pennsylvania Sen. Rick Santorum.

Bachmann, at the direction of police, entered through a side door, and was greeted with cheers from volunteers, many of them college students from Oklahoma.

"I appreciate your Christian faith," said Afame Ooceeh, a 29-year-old pre-med student. "I support you with all my heart."

Ooceeh, originally from Nigeria, is part of a contingent of 42 students from Oral Roberts, a Christian university where Bachmann attended law school. The group, which arrived Thursday, is chaperoned by Winston Frost, a professor who was in Bachmann's class.

"She was one of the most diligent students in the class," Frost told NBC News.

Later, Bachmann sat at a table and placed several calls as a scrum of television cameras rolled.

She reached one voter, Bob Johnson, telling him, "Let everybody know – come on out and caucus for me on Tuesday."

After she hung up, a volunteer urged her to ring the bell that signifies a voter won.

"We’re going to ring it a couple times," Bachmann said to cheers, "because Bob is going to go on a recruiting mission."

NBC's Anthony Terrell contributed reporting.