Democrat were described by Rudy Giuliani as impractical, while the presidential hopeful republican considered himself as realist on foreign policy with experience at the negotiating table.
Giuliani described Democrats late Thursday as "falling all over themselves" to negotiate quickly and without preconditions with hostile foreign leaders - a reference to sparring between Democratic candidates Sen. Barack Obama and Sen. Hillary Rodham Clinton over how best to deal with Iran.
"It's a spectacle of almost begging your enemy to negotiate with you," Giuliani said in a speech to donors at a Las Vegas casino. "Democrats don't get it ... I think the big difference in voting for me is you will have as president of the United States a realist who has experience negotiating."
Giuliani contended that experience came from his two terms as New York mayor.
Leading Democrats in the race have "never had to make practical decisions, or negotiate with other business or with unions ... so they have exceedingly impractical ideas," he argued. "This is not the time to give these people on the job training as executives."
Giuliani aimed all of his criticism at Democrats, leaving largely unmentioned his Republican foes in the campaign.
He did not take questions from the media and did not comment on news that his longtime associate and former New York City Police Commissioner Bernard Kerik had been indicted on federal corruption charges.
Kerik was to be arraigned Friday. Giuliani has said he made a mistake in recommending Kerik as head of Homeland Security in 2004.
The former mayor praised his longtime friend retired Judge Michael Mukasey on his Senate confirmation as attorney general.
He characterized Democratic attempts to thwart the confirmation as political. Mukasey had come under fire by Democratic senators after refusing to say whether the waterboarding interrogation practice was torture.
The waterboarding debate was "a real clear indication of what's at risk, and what we've got to fight for," Giuliani argued. "Those of us who believe that we have to remain a country that has the Patriot Act, a country that has electronic surveillance to use to find out about these plots that may be being planned, a country that does use, not torture - America should never use torture - but we have to use aggressive questioning to get information from people."