Six Democratic presidential candidates spoke at the Iowa Federation of Labor convention in Waterloo Wednesday.

Chris Dodd, the first to speak, called for cutting off imports of toys and food from China. Dodd said working for fair trade is part of the union movement.

"The middle class exists in this country…because people have fought tooth and mail to secure wages and salaries and benefits and working conditions that were not given out as a gift," Dodd said. "There are those who came before all of you in this room who shed blood and died, in fact, to secure those rights."

Barack Obama promised to strike more "worker-friendly" trade agreements if he’s elected president. "If it’s only good for the Dow Jones, but it’s not good for Jim Jones or Fred Jones, I don’t want to be part of that trade agreement," Obama said.

John Edwards drew loud cheers from the labor crowd when he called for making union jobs more secure. "We need to make…banning the permanent replacement of strikers the law of the land," Edwards said. "No scab should be able to walk through your picket line and take your job when you’re involved in a strike."

Hillary Clinton said if she’s elected, her Department of Labor will be a friend rather than a foe to organized labor. "We have to get back to supporting unionization," Clinton said. "And we can’t do that if we don’t have laws and people enforcing those laws who actually believe it."

Joe Biden and Bill Richardson also spoke at the union convention.

Radio Iowa