Former speaker of the US House of Representatives Newt Gingrich defended himself in his first debate as the new front-runner for the Republican presidential nomination, with less than a month to go before the leadoff vote to determine President Barack Obama's 2012 challenger.
Gingrich has risen to become the new target in the race, and former Massachusetts Governor Mitt Romney has criticised him directly in recent days after leading in earlier national polls.
The candidates were debating in Iowa, where precincts caucuses on 3 January begin the process of selecting delegates to the Republican National Convention next summer.
The night's topics largely focused on domestic instead of foreign affairs, but Gingrich was again questioned about his comments the day before in which he said that Palestinians were an "invented" people. Gingrich tried to clarify his statements before the debate, saying he supported a negotiated peace agreement between Israel and the Palestinians, including a Palestinian state.
Romney said Gingrich had made it more difficult for Israelis and Palestinians to negotiate toward peace. Gingrich responded by saying he was speaking as a historian, but added that it was time for a candidate to stand up and call Palestinian leaders "terrorists."
On the domestic front, Romney again emphasised his experience as a businessman in the private sector and suggested that Gingrich's background as a Washington insider would be a liability. Gingrich fought back, telling Romney, "The only reason you didn't become a career politician is because you lost to Teddy Kennedy in 1994," in a US Senate bid. Romney quickly retorted: "If I'd been able to get in the NFL as I'd hoped as a kid, I could have been a football star too," referring to America's professional football league.
Gingrich's decision to invoke Kennedy, the late senator, served as a dual reminder – that Romney has been running for office since the mid-1990s and also that he lost to the man whose politics conservatives detested above all others.
For his part, Texas Governor Rick Perry made a remark aimed at Gingrich, who has admitted past infidelity, saying, "If you cheat on your wife, you'll cheat on your business partner. It's a characteristic people look at." Despite such comments, the tone of the debate was generally respectful.
Both Perry and Minnesota Representative Michele Bachmann tried to tie Romney and Gingrich together, calling them not conservative. Both Romney and Gingrich still face scepticism from the conservative tea party movement.
Bachmann referred repeatedly to "Newt-Romney," saying the two held similar views on health care, illegal immigration, cap-and-trade legislation and the payroll tax cut extension. On immigration, Gingrich repeated his view that immigrants illegally in the US should be allowed to earn legal residency under certain conditions. Romney disagreed.
But all candidates agreed they must attack unemployment and revitalise an anaemic economy, which looms as the top issue in the election.
The debate was the twelfth debate of the Republican nominating campaign and the first since Herman Cain suspended his campaign a week ago amid allegations of sexual impropriety.