Republican presidential hopeful Mike Huckabee said Monday he was tough on crime as Arkansas' governor, rejecting a new television ad by rival Mitt Romney that implied he was soft.

The new spot, airing in Iowa, where Huckabee has knocked Romney out of first place in the polls, says Romney never pardoned a criminal when he was governor of Massachusetts. The ad goes on to quote from a recent Associated Press report that said Huckabee issued 1,033 pardons and commutations during his more than 10 years as Arkansas governor.

The ad's conclusion: "On crime, the difference is judgment."

Huckabee disagreed.

"The difference between us is that I did something he never had to do. I carried out the death penalty 16 times, more than any other governor in my state's history," Huckabee told reporters in Los Angeles before attending a Beverly Hills fundraiser. "That's hardly soft on crime when you make that tough decision and actually carry it out."

The anti-abortion Huckabee said letting a death sentence go forward was the most "challenging" thing he faced as governor.

"I read every single page of every file of every case" that came to his desk, Huckabee said. "It's the one thing that's irrevocable."

Romney's state of Massachusetts does not have capital punishment. A Romney spokeswoman said Monday that he "supports the death penalty."

As Huckabee's popularity rises, he's having to spend more time defending himself instead of talking about his campaign.

Not surprisingly, he sounded Monday as if he wanted to declare a holiday truce among the Republican presidential contenders.

"I think the country could use a little good will and peace on earth a little more than they can some tit for tat in the political arena," Huckabee said.

He even seemed to hold out an olive branch of sorts, congratulating Arizona Sen. John McCain on his recent endorsements, including Monday's nod from former Democratic vice presidential nominee Sen. Joe Lieberman of Connecticut.

Huckabee joked that he's available for endorsements, too.

"If somebody out there hasn't made an endorsement yet and would like to," he said, "I volunteer to be the endorsed."