Newt Gringrich, one of the few serious candidates in the GOP primary now that Mike Huckabee is out, may have just shot himself in the foot with GOP primary voters.

An Iowa voter said the following to Gringrich on Monday as he toured through the state.

“What you did to Paul Ryan was unforgivable,” said the voter.

“I didn’t do anything to Paul Ryan,” said Gingrich.

“Yes you did. You undercut him…You’re an embarrassment to our party.  Why don’t you get out [of the presidential race] before you make a bigger fool of yourself,” said the voter.

The incident was captured by Fox News on video footage.

Gringrich angered the Iowan and many other GOP voters with his attacks against GOP House Budget Committee Chairman Paul Ryan’s Medicare and budget plans.

On Sunday on Meet the Press, the former Speaker of the House described it as “a conservative imposing radical change” and “right-wing social engineering.”

The backlash was immediate.

“Here you've got Representative Ryan trying to bring common sense to this world of insanity, and Newt absolutely cut him off at the knees, said GOP South Carolina Governor Nikki Haley on CNN.   

On Laura Ingraham’s radio show, Ryan said:  “with allies like that, who needs the left?”