Barack Obama sharpened his attacks on Hillary Clinton last night, accusing her of speaking disingenuously about their senate records and campaign proposals.
The heightened criticism, which came less than 48 hours before Nevada Democrats choose their presidential nominee, was a marked departure from Obama's rhetoric in Iowa and New Hampshire, where he rarely mentioned Clinton by name.
Obama told a rally at a Las Vegas high school that Clinton had misrepresented his views on social security and a proposed nuclear waste dump in Nevada.
He also poked fun at a remark Clinton made during a debate this week, in which she acknowledged voting for a bankruptcy bill even though she said she was glad it did not pass. "What does that mean?" he asked. "If you didn't want to see it pass, then you vote against it."
Clinton, Obama and John Edwards are in a virtual dead heat ahead of the caucuses. But Obama's failure to mention Edwards by name suggests his campaign is happy to present it as a two-person race.
Obama and Clinton split victories in Iowa and New Hampshire, respectively, and both hope a win in Nevada will generate momentum to propel them through South Carolina next week and into February 5, when more than 20 states vote in Super Tuesday.
The campaign in Nevada has also turned into a proxy battle among the state's strong labour organisations. The state chapter of the Service Employees International union and the powerful Culinary Workers' union have endorsed Obama. The Carpenters' union, which has a large membership in Nevada, backs Edwards.
The Nevada State Education Association, the teachers' union, has not endorsed a candidate, but some in its leadership have ties to the Clinton camp. The teachers' union also sought unsuccessfully to block the Democratic party from holding special caucuses for Las Vegas casino workers, a bid to temper the culinary workers' endorsement of Obama.
Obama's criticism of Clinton is in large part a defence of his own proposals, such as his plan to shore-up social security.
At a debate last year, Clinton referred to Obama's plan to lift the wage cap on payroll taxes as a "trillion-dollar tax increase". Currently, income under $97,500 per year is subject to that tax. Obama said only 3% of Nevadans make more than that.
"Maybe she thinks that's middle class," he told the rally. Obama said Clinton's remark was a distortion that turned voters off the political process. Those kinds of tricks, that kind of approach to politics is what has to stop. What happens is then nobody believes anything. The voters don't believe what politicians say."
A senior strategist with the Obama campaign said that Obama's criticism of Clinton was the result of lessons learned during political battles with Republicans. "We're not going to let some of these assertions go unchallenged," David Axelrod said of Clinton's statements about Obama.
"She's distorted his record. Part of this process is straightening that out. Abraham Lincoln once said, 'If they don't stop telling lies about us we're going to have to tell the truth about them.'" The Clinton campaign did not immediately respond to a request for comment.
The rally-goers revelled in Obama's fighting words, cheering when he jabbed at Clinton and laughing when he poked fun at her. "He can attack Hillary. He doesn't have to take this stuff," said Angela Robinson, a Las Vegas art gallery owner.
"But he's being a real diplomat and a real statesman. He's not telling you what's wrong with her, he's telling you what's right about him."