Rudy and Mitt stepped up the attacks against each other over the weekend. Hizzoner ups the ante even more in an interview with Jonathan Martin published this morning:

WINDHAM, N.H. - In a big strategic shift, Rudy Giuliani hammered Mitt Romney's record on three fronts, saying it was time to "take the mask off and take a look at what kind of governor was he."

Using some of the toughest language of his campaign, Giuliani, in an interview with Politico, slammed Romney on health care, crime and taxes. At the same time he portrayed the one-time moderate as a hypocrite on a host of social issues who lives "in a glass house." It was easily the most sweeping attack Giuliani has delivered against Romney in this campaign.

"He throws stones at people," Giuliani said in an interview on his campaign bus. "And then on that issue he usually has a worse record than whoever he's throwing stones at."

The Romney camp responded by calling Giuliani's attack "nasty" and offering a point-by-point rebuttal.

Meanwhile, on the Democratic side Hillary is stepping up her attacks on Barack Obama - so much so, in fact, that Mike Allen and Carrie Budoff argue that Obama is now "barnstorming Iowa with a front-runner's swagger" while Clinton is scrambling across the state "like an underdog."

So the question is, how will this "new phase" of the campaign wear on all the players involved? Will Rudy come off as "nasty" or will his back and forth with Romney be seen as reinforcing the image that he's a tough, no-nonsense street fighter from Brooklyn and exactly the kind of candidate Republicans want for the general election? How will Democrats perceive Clinton? I don't know that we know the answer to these questions yet, but we can probably say it hurts Hillary Clinton more to be in attack mode because it brings back the hard edge to her personality that her campaign has spent months trying to soften and also because her attacks play directly to one of Obama's strengths as a candidate. The same isn't true on the Republican side.

And let's not forget how these nasty, high profile mano-a-mano battles potentially open the door for others - especially on the Republican side where you have Huckabee surging in Iowa, McCain lurking in New Hampshire, and Fred Thompson trying to find a way to keep his name in the mix long enough to make it to South Carolina.

Christmas is coming, but don't bother hanging up any mistletoe for these folks. With just over one month before Iowa, it's brass knuckle time now.

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