Politico:

Mitt Romney compared them to Karl Marx. Rudy Giuliani came right out and used the S-word (socialist). And John McCain poured salt in the wounds.

Reluctant to start slugging each other at this early stage of the campaign and still hesitant to directly criticize President Bush, the top GOP presidential candidates have found another way to vent their building aggression: pounding on their would-be Democratic rivals.

Each has stepped up his rhetoric in recent days, sharpening attacks on Sen. Hillary Rodham Clinton (N.Y.), Sen. Barack Obama (Ill.) and former North Carolina Sen. John Edwards.

At Sunday’s GOP debate, Romney said Obama has “gone from Jane Fonda to Dr. Strangelove” for stating his willingness to meet unconditionally with hostile foreign leaders but at the same time warning that he would attack al-Qaeda forces in Pakistan without that country’s consent.

Giuliani, meanwhile, said the leading Democratic contenders ”haven’t run a city, a state, a business.”

” I think maybe they’ve run a club somewhere,” he joked, a veiled gibe at Clinton’s having once been president of the Wellesley College Republicans, according to an aide. 

For the Republican hopefuls, the strategy is a mix of exasperation, calculation and desperation. Frustrated at the constant drumbeat of negative stories about their president and party, the candidates want to change the narrative.

But it’s too politically risky at this point to lash out against one another, let alone Bush. So the obvious and safe alternative is to tee off on the Democratic contenders.

But the attacks aren’t just empty exercises in blowing off steam by top-shelf political performers. In a difficult climate, the Republican top tier recognizes the need to steadily begin reminding its own voters and the broader public about what a Clinton or Obama administration would bring.