BOCA RATON, Fla. — Facing a pivotal primary in Florida next week, Republican presidential candidates jousted yesterday over who has the best background to deal with the nation's economic slump.

John McCain stressed his congressional efforts to cut "pork barrel spending," Mitt Romney his business background and Rudy Giuliani his tenure as mayor of New York City.

"We will clean up our act," said McCain, the Arizona senator, when asked about surveys showing that voters now have less confidence in President Bush and the Republican Party on economic policy.

McCain is atop state polls with Romney, who said he would promote his credentials as a venture capitalist, Olympics organizer and Massachusetts governor. The primary is Tuesday.

Giuliani, who is trying to salvage his presidential campaign with a strong showing here, said his performance as mayor shows he can turn around a government. Giuliani is third in the latest polls, but he predicted he would emulate the New York Giants' football victory Sunday over the Green Bay Packers.

"We're going to come from behind and surprise everyone," he said.

Mike Huckabee, who has been criticized for raising some taxes while Arkansas governor, defended his record. Texas Rep. Ron Paul lamented that Republicans "haven't been acting like Republicans."

All of the candidates except Paul stood by the Iraq war, and said the current strategy is now working. McCain said the war was "a good idea," but was "not worth the failures" that immediately followed the toppling of Saddam Hussein.

The 90-minute debate at Florida Atlantic University, broadcast on MSNBC, came just hours after Bush and congressional leaders announced a deal to boost the economy. The candidates said it was a good start, but all promised to do more if they got elected.

McCain is trying to attract more GOP votes in a primary restricted to those in the party. He was asked about criticism from radio host Rush Limbaugh and others who say he is not sufficiently conservative.

McCain cited his efforts to curb federal spending and support of conservative judges.

Romney is looking to win a contest in which all of his opponents are competing. He won the primary in his native state of Michigan, as well as little-contested caucuses in Nevada and Wyoming.

Giuliani defended his strategy of largely ignoring previous contests and concentrating on Florida. He led several pre-election polls here last month but has been dropping since the Iowa caucuses Jan. 3.

Huckabee is trying to recover from his second-place finish to McCain in South Carolina.