Las Vegas ? Under pressure in a feisty debate, Sen. Hillary Rodham Clinton accused her closest rivals Thursday night of slinging mud “right out of the Republican playbook” and leveled her sharpest criticism of the campaign at their records.

“People are not attacking me because I’m a woman, they’re attacking me because I’m ahead,” Clinton said, striving to protect her standing as front-runner in an increasingly competitive nominating campaign.

“What the American people are looking for right now is straight answers to tough questions, and that is not what we have seen from Senator Clinton on a host of issues,” said Sen. Barack Obama of Illinois in the opening moments of a debate seven weeks before the first contest of the race for the Democratic presidential nomination.

“There’s nothing personal about this,” said former Sen. John Edwards of North Carolina, who joined Obama in bluntly accusing Clinton of forever switching positions on Social Security, driver’s licenses for illegal immigrants and other issues, turning aside the suggestion that she was seeking to hide her positions. Long an advocate of universal health care, she said Obama’s current proposal leaves millions uncovered and that Edwards did not support health care for all when he first ran for president in 2004.

For Richardson, Sens. Joseph Biden of Delaware and Chris Dodd of Connecticut and Rep. Dennis Kucinich of Ohio, the opening moments were frustrating – and they repeatedly tried to break in.

“Oh, no, don’t make me speak,” Biden said in mock horror when moderator Wolf Blitzer of CNN called on him roughly 15 minutes into the proceedings.

New Mexico Gov. Bill Richardson, who has campaigned in Nevada more than any other presidential hopeful, took verbal shots at Clinton and her two closest pursuers in the polls.

“Let’s stop the mudslinging,” he said.