By John Whitesides, Political Correspondent LAS VEGAS, Nov 15 (Reuters) - Democratic presidential front-runner Hillary Clinton fired back at her rivals for "throwing mud" on Thursday in a contentious debate marked by sharp clashes with opponents Barack Obama and John Edwards. Clinton, who has a huge lead among Democrats in national polls, went on offense early in the first face-to-face encounter with her rivals since an Oct. 30 debate where her candor and ability to give straight answers to tough questions came under fierce attack. "When somebody starts throwing mud at least we can hope it's accurate and not right out of the Republican playbook," Clinton said in response to criticisms from Edwards of her stances on foreign policy and Social Security. Clinton, a New York senator who has proposed a universal health care plan, criticized Obama's health care plan for leaving about 15 million Americans without health insurance coverage and said there was a big difference from her plan. "I don't think the problem with the American people is that they are not being forced to get health care, the problem is they can't afford it," Obama, an Illinois senator, argued. The sharp opening exchanges were criticized by New Mexico Gov. Bill Richardson and Delaware Sen. Joseph Biden, who slammed the continued Democratic assaults on each other. "Let's stop this mud-slinging," Richardson said. Clinton has been under attack since the last debate, when her failure to take a stand on questions about whether illegal immigrants should get driver's licenses opened the door for her opponents to paint her as too cautious and calculating. The former first lady's performance in that debate gave new hope to rivals trying to narrow her lead in national polls and beat her in Iowa, which in seven weeks opens the state-by-state battle in each party to pick nominees for the November 2008 election. (Editing by Lori Santos) (To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at http://blogs.reuters.com/trail08/)
