MANCHESTER, N.H. ? Democratic presidential candidates sparred, sometimes intensely, over who among them was the true change agent, while their Republican counterparts held a virtual tea party Saturday night, as both groups held back-to-back debates just days before New Hampshire’s Tuesday primary.

New York Sen. Hillary Clinton went on the attack, challenging Illinois Sen. Barack Obama and former North Carolina Sen. John Edwards on their records and insisting that her life proves she can achieve change while they just talk about it. They came back at her with equal zeal, double-teaming her at times.

Republicans, on the other hand, basically agreed with each other on almost everything, except that Arizona Sen. John McCain couldn’t hide his contempt for former Massachusetts Gov. Mitt Romney’s record of reversing positions on fundamental issues.

The clash between the four Democrats was their first since Obama trounced Clinton in Thursday’s Iowa caucuses, and the last before New Hampshire voters cast the nation’s first secret ballots for presidential nominees on Tuesday.

Obama is leading narrowly in many New Hampshire polls.

While the Democrats sparred over domestic issues, most of their differences were more of tone, nuance and resumes. They all want to end the war in Iraq. They all want aggressive programs to reduce U.S. dependence on foreign oil. They all want to extend health insurance to everyone. They disagreed mainly on who would best be able to do it.

Republican presidential candidates turned to critique the one prominent Republican not onstage with them: President Bush and his foreign policy.

Candidates took turns differing with Bush, particularly on his initial Iraq war strategy, which most of them called weak and former Arkansas Gov. Mike Huckabee called “arrogant.” Most hedged their criticism, however, with praise and defense of the rest of Bush’s defense strategy and his conduct of the war on terror.

Polls showed McCain leading in New Hampshire, followed by Romney. They also pointed to a four-way battle for third place among Huckabee, former New York Mayor Rudy Giuliani, Rep. Ron Paul of Texas and former Tennessee Sen. Fred Thompson.

One familiar point of tension came over illegal immigration – Romney again criticized McCain for backing a plan that would allow illegal immigrants to remain in the United States.