-- Democratic presidential candidate John F. Kerry should tap Rep. Richard A. Gephardt (Mo.) for vice president as a way to maximize union enthusiasm and turnout this fall, James Hoffa Jr., president of the Teamsters, said Sunday.

Hoffa, in town for the International Brotherhood of Teamsters annual conference, told reporters he has lobbied Kerry three or four times to pick Gephardt because of his unwavering support of organized labor's political and policy agenda. The union endorsed Gephardt during the Democratic primaries and threw its support behind Kerry only after Gephardt and other Democrats dropped out of the race.

"I think Dick Gephardt does bring a comfort level with regards to organized labor," Hoffa said in an interview at Bally's Hotel Casino. "He's traveling with John Kerry today, so I think things are coming along."

Gephardt was in town for the conference but not traveling with Kerry, according to David Wade, a spokesman for the presumptive Democratic nominee. Wade would not comment on Gephardt's chances of getting the nod.

Although Hoffa spoke favorably and at times enthusiastically about Kerry, the Teamsters president and many other union leaders have expressed concerns about the senator's record on labor issues, especially trade.

In the Senate, Kerry voted for the North American Free Trade Agreement and admitting China into the World Trade Organization, which organized labor -- and Gephardt -- opposed. "In the future, he will have a different record," Hoffa predicted.

As a presidential candidate, Kerry has advocated trade as a way to create U.S. jobs but criticized President Bush for failing to enforce existing trade agreements. Kerry flew for five hours Sunday morning to bring his message to Las Vegas and raise money at an early evening fundraiser at the Four Seasons.

Speaking at the Teamsters conference, Kerry faulted Bush for creating a record-high $46 billion trade deficit in March -- in part, he said, by refusing to enforce labor and environmental standards already on the books.

"This is not a philosophical question," Kerry said. "This really is something that goes to our values system. It's a common-sense question: Why aren't we enforcing our own laws on behalf of our own workers and business?"

If he were elected president, he would appoint a commission to report back within 120 days on trade deals and enforcement. Offering one clear trade policy distinction with Bush, Kerry said he would not sign the Central American Free Trade Agreement as written unless tougher worker and environmental provisions were incorporated.

But, he cautioned, "I am not a protectionist." With Gephardt sitting in the front row, Kerry lauded the congressman as one of the most principled and hardworking politicians he has worked with in the past 20 years.

Gephardt is one of several potential running mates considered seriously by the Kerry campaign. The list also includes Democratic Sens. John Edwards (N.C.) and Bob Graham (Fla.), Iowa Gov. Tom Vilsack (D), Republican Sen. John McCain (Ariz.) and others.

Sen. Joseph R. Biden Jr. (Del.), the ranking Democrat on the Senate Foreign Relations Committee, said on NBC's "Meet the Press" Sunday that McCain would be the ideal pick to heal the nation's wounds in bipartisan spirit.

"Do I think it's going to happen? No," he said. "But I think it is a reflection of the desire of this country, and the desire of people in both parties, to want to see this God-awful, vicious rift that exists in the nation healed, and John and John could go a long way to healing that rift."

The campaign has kept deliberations secret, and some Democrats see one big advantage in stretching out a final decision: The competition for vice president is prompting many Democrats to redouble their fundraising and political assistance for the campaign in hopes of catching the candidate's eye. Retired Gen. Wesley K. Clark, for instance, has been raising money and calling reporters to advocate for Kerry. Last week, Clark, a potential vice president thanks to his southern roots and military experience, accompanied Kerry back to Washington.

Hoffa said Gephardt could help deliver the battleground state of Missouri and other swing states in the Midwest, where trade issues are paramount.