Speaking before the Conservative Political Action Conference in suburban Washington on Thursday, Wisconsin Gov. Scott Walker was asked how he would handle the threat of the Islamic State if he were in the White House. 

Walker, who has emerged rapidly as a leading Republican presidential contender for 2016, cited his leadership abilities as governor and then made an analogy: "If I can take on a hundred thousand protesters, I can do the same across the world," he said, a reference to the huge demonstrations that erupted in Madison in 2011 over his repeal of collective bargaining rights for most public employees.

The CPAC crowd applauded, but Walker and his staff quickly tried to provide some context after the speech. 

“What the governor was saying was when faced with adversity he chooses strength and leadership,” a representative said.

Still, the apparent comparison between terrorists and pro-labor demonstrators is drawing rebuke from across the political spectrum.

Unions were predictably outraged.

“To compare the hundreds of thousands of teachers, students, grandmothers, veterans, correctional officers, nurses and all the workers who came out to peacefully protest and stand together for their rights as Americans to ISIS terrorists is disgusting and unacceptable,” said Phil Neuenfeldt, president of the Wisconsin AFL-CIO.

"Our union's building was a block away when the Twin Towers fell on 9/11," Jim Tucciarelli, a New York City sewage worker represented by the American Federation of State, County and Municipal Employees, said in a statement. "I have friends who died on that terrible day. In the weeks that followed, union members worked tirelessly to bring the city back, and I am proud to have been one of them. Governor Walker, I know terrorism. I know that your own state's citizens speaking up for what's right isn't terrorism."

Walker's comments also drew some unlikely critics. Former Texas Gov. Rick Perry, a once and possible future presidential contender who is well accustomed to making and justifying controversial statements of his own, said he thought Walker went too far.

"These are Americans," Perry, who is also at CPAC this year, told MSNBC. "You are talking about, in the case of ISIS, people who are beheading individuals and committing heinous crimes, who are the face of evil. To try to make the relationship between them and the unions is inappropriate.”

Writing in the conservative National ReviewJim Geraghty called the response "terrible."

"Secondly, it is insulting to the protesters, a group I take no pleasure in defending," Geraghty wrote. "The protesters in Wisconsin, so furiously angry over Walker’s reforms and disruptive to the procedures of passing laws, earned plenty of legitimate criticism. But they’re not ISIS. They’re not beheading innocent people."