While ignoring Tuesday’s primary contests, former House speaker Newt Gingrich was finding an old niche.

After a month of sparring with former Massachusetts governor Mitt Romney, Gingrich has returned to more comfortable territory — criticizing President Obama with language more incendiary than his rivals would dare to use.

In Georgia Tuesday, he called Obama “so pro-Islamic that [he] can’t even tell the truth about the people who are trying to kill us,” the latest in a series of recent attacks on the White House as excessively friendly to Muslims.

In last week’s debate, he used his opening remarks to promise that “no future president will ever bow to a Saudi king again.”

And over the past few days Gingrich has repeatedly criticized Obama for apologizing to Afghan President Hamid Karzai over the accidental burning of Korans by U.S. military personnel.

“I think we can look into the mind of a president in the speed and thoroughness with which they have disowned their own people,” Gingrich said Tuesday. Earlier in the week, he said President Obama had “surrendered.”

He has suggested U.S. troops pull out after two American soldiers were killed by a person in an Afghan army uniform during the backlash unless Karzai apologized back.

He brought it up again in his speech later that night.

While both Romney and former Pennsylvania senator Rick Santorum followed Gingrich’s lead and criticized Obama’s apology on Sunday, neither was so combative and neither dwelled on the issue.

“To apologize for something that was not an intentional act is something that the president of the United States, in my opinion, should not have done,” said Santorum.

“We’ve made an enormous contribution to help the people there achieve freedom, and for us to be apologizing at a time like this is something which is very difficult for the American people to countenance,” said Romney.

The focus on Islam is a return to form for Gingrich, who in May of last year warned of a United States “potentially . . .dominated by radical Islamists and with no understanding of what it once meant to be an American.” In 2010, he compared Muslims hoping to build an Islamic Center near the World Trade Center site to Nazis.

Republican candidates “believe they have nothing to lose and everything to gain by pandering to anti-Islamic bigotry,” said Ibrahim Hooper, spokesman for the Council on American-Islamic Relations. “It’s always been under the surface, ready to pop up at any moment.”

But it’s not certain that this strategy will win Gingrich votes so much as headlines. His May 2011 comments were not followed by a surge in polls.