Republican National Committee Chairman Ed Gillespie (searchcriticized Democrats on Thursday for questioning President Bush's military service, calling it "the dirtiest campaign in modern presidential politics."

Gillespie was in Nevada to greet supporters in Las Vegas and give a dinner speech in Reno.

In remarks prepared for the dinner, Gillespie went on the offensive against Democrats.

"Their patently false charges are just one indication of the type of campaign Democrats will run," Gillespie said.

In the speech, Gillespie questioned Sen. John Kerry's (searchcommitment to national security while offering brief praise for the Massachusetts Democrat's military record in Vietnam.

A spokesman for Kerry's campaign dismissed Gillespie's comments as "the right-wing smear machine at it again."

Gillespie also called Democratic National Committee Chairman Terry McAuliffe (searchthe "John Wilkes Booth of presidential character assassination" for accusing Bush of skirting his duties with the National Guard.

DNC press secretary Tony Welch said the controversy over Bush's military records is growing despite administration and Republican Party efforts, he said.

The White House released dental records Wednesday to support Bush's account of his Air National Guard service in Alabama, where at the time he was working as an aide on a political campaign. But several members of his unit have said they don't remember ever seeing Bush at their Montgomery base. Bush also served in the Guard in Texas.

Gillespie's trip comes two days before Nevada's Democrats hold caucus meetings to survey their preferences for a presidential nominee.