WATERLOO - Six Democratic presidential candidates took aim at President George W. Bush's record on workers' rights at the Iowa Federation of Labor convention Wednesday in Waterloo.

In front of about 200 Iowa union leaders and delegates and a throng of national media, the candidates criticized Bush for policies they say have put Americans out of work at the same time he has given tax cuts to the wealthy.

North Carolina Sen. John Edwards said Bush should be blamed for the loss of 3 million American jobs since he took office, and for rolling back workplace protections and overtime pay.

"He has taken a 2-by-4 to the American dream," Edwards said.

Rep. Dick Gephardt of Missouri, a longtime favorite of labor, reminded the crowd he led the fight against the North American Free Trade Agreement and other pacts blamed by unions for the loss of millions of American jobs. Without naming them, Gephardt noted other Democratic presidential candidates supported NAFTA when it was passed 10 years ago.

"Before you come down in this race, check the record. I'm there - I've always been there. And I will not rest until we get trade right, until we protect the jobs of American workers," Gephardt said.

Having won endorsements from 11 international unions, Gephardt hopes to secure the coveted endorsement of the national AFL-CIO, an umbrella group with 13 million union members.

Richard Trumka, the secretary-treasurer of the national AFL-CIO, said unions plan to step up their efforts to oust Bush next year, putting in place the most widespread voter registration and mobilization effort the organization has ever launched. Trumka said if the national AFL-CIO endorses a candidate, it most likely would be Gephardt, but only if he goes wins sufficient backing from two-thirds of the AFL-CIO member unions.

"After the primaries are over, we'll be in lockstep come the general election, because Bush's policies have been so bad and so hostile to the working people," Trumka said.

Massachusetts Sen. John Kerry, who met with striking workers at Eagle Ottawa Tannery in Waterloo before the forum, said it's time the federal government enforces laws that prevent employers from retaliating against workers who attempt to unionize. Kerry also criticized tax cuts advocated by Bush that have gone to the wealthiest Americans, saying it is the wrong way to try to stimulate the economy.

"Everyone I've met in America is kind of tired of being trickled on by the Bush economy," Kerry said.

Florida Sen. Bob Graham, another Democrat who wants to see a repeal of tax cuts to the richest taxpayers, said Bush is promoting giveaways to companies that take jobs overseas while he has "slammed the door shut on opportunities for America's working families."

"America is being divided," Graham said. "George Bush lives in an America in which he has promoted a growing gap between the wealthiest Americans and working Americans."

Former Vermont Gov. Howard Dean, who has called for a complete repeal of the Bush tax cuts, said the money should have been used to invest in schools, roads and energy development, which he said would have been a better way to create jobs.

"The bottom line is, most people in America would be glad to pay the same taxes they paid when Bill Clinton was president, if only they could have the same economy they had when Bill Clinton was president," Dean said.

Ohio Congressman Dennis Kucinich argued foreign trade agreements like NAFTA should be canceled rather than modified to improve foreign labor and environmental standards, a move the other candidates have called for.

IFL president Mark Smith asked Kucinich if he might be labeled as too far left of the political mainstream. Kucinich said only a candidate who offers a fundamental difference from Bush will be able to win.

"I'm the candidate who presents the sharpest contrast to this administration," he said.

Connecticut Sen. Joe Lieberman did not attend the forum because of a scheduling conflict. The Rev. Al Sharpton and former U.S. Sen. Carol Moseley Braun also were absent.