Robin Hensel and Larry Frost are about as far apart ideologically as you can get.

She's a peacenik grandmother who rails against "the 1 percent," big corporations, war and what she sees as unequal access to health care.

He's a lawyer and former military intelligence officer who is nearly in the 1 percent. He believes in the free market, conservative politics and the U.S. Constitution; in fact, while in the service he carried a copy in his pack for nine years.

Hensel and Frost do agree on at least one thing, however, which makes this previously powerless resident suddenly dangerous to the city of Little Falls, Minn.: free speech.

I wrote about Hensel back in February. The city, citing local ordinances, told her to take down protest signs in her yard. In response, she pointed out that the "Support our troops" sign downtown, as well as others, also violated ordinances. Because of her complaints, she received threats on Internet sites.

Frost contacted me, offering to help Hensel. "I not only oppose, I despise Hensel's viewpoints," he wrote. But he also thought the city was being a "bully" and unfairly targeting Hensel because of the content of her signs. At the time, he said if the city didn't stop hassling her, he would consider a lawsuit.

On Monday, Frost sued Little Falls in U.S. District Court in Minneapolis, adding high-powered attorney Bruce Fein, an expert in constitutional and civil rights law who was a high-ranking attorney during the Reagan administration's Justice Department and who worked for the American Enterprise Institute and the Heritage Foundation, two conservative think tanks.

Uh-oh.

Hensel, a caregiver for troubled kids, suddenly has some powerful allies in her fight against City Hall.

The complaint alleges:

"The city of Little Falls has no excuse in law for wrongfully harassing a 58-year-old grandmother because she colorfully expressed an unpopular viewpoint on her own property. And that is exactly what the Defendant City did. Indeed, at every turn the Defendants brandished their government authority to suppress or burden Plaintiff's viewpoints because of hostility to their ideas and to facilitate and promote viewpoints they found agreeable."

Neither the city's city attorney nor its police chief, who was named in the lawsuit, returned calls.

The suit challenges both the wording of the city's ordinance and the way it has been enforced. Frost says the city forbade political speech while allowing commercial speech, and treated Hensel differently from others on several occasions. Furthermore, the suit claims the city officials' actions were "malicious," and it seeks damages.

"You won't believe the antics [by] the city," Frost said in an e-mail. "For example, the council has refused to allow Robin's demonstration to camp overnight in a city park, citing the regulation forbidding the same, but has allowed commercial enterprises/speech to do so for years. And they allowed a 1,000-man caravan to camp overnight in 2010, including allowing drinking in the parks, also illegal under city ordinances. The city appears to be bending over backwards to make my case for me. I'm much obliged.

"Basically, they have gotten this wrong every way they could get it wrong," Frost said. He said the council claimed to not know about groups camping in the park even though it's six blocks from City Hall.

As for the threats against Hensel, Frost sent a note earlier this month to Greg Schirmers, the city's chief of police, alleging that authorities were not taking the threats seriously. Although some were posted on websites based out of state, Frost noted that the poster could be in Minnesota. One threat mentioned nearby Camp Ripley and used the term "lock and load." Another threatened her with a bat.

Hensel is taking the threats seriously. Frost said he just learned that she stopped providing respite care for families with difficult kids because she feared for their safety.

Hensel is learning that free speech can have a high price. I'm guessing the city of Little Falls will, too.

jtevlin@startribune.com • 612-673-1702