New Mexico Gov. Bill Richardson told a building trades union on Tuesday that he would be an activist president on behalf of labor unions if elected. The governor and Democratic presidential candidate made his case before a meeting of the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry. The group is nearing a decision about an endorsement. "I want you to know that if I were elected president, just as I've been an activist governor and an activist secretary of energy, I will be an activist president on your behalf," he said.

The union, known as the UA, has about 300,000 members nationwide, and 5,000 in Nevada, where Richardson hopes a strong showing in the Jan. 19 caucus will bolster his candidacy.

Courting the building trades can be tricky for some Democrats in the race.

The union supports expansion of the nuclear industry and the opening of a nuclear waste storage dump at Yucca Mountain, a project 90 miles northwest of Las Vegas that promises hundreds of new jobs but is opposed by most of the state's residents and public officials.

Union members also trend more conservative on the Iraq war, gun control and abortion rights.

On energy, Richardson promised to push for a "broad breadth of options." He emphasized his support for biodiesel, biofuels and included nuclear energy among the options.

"Nuclear today, it doesn't emit greenhouse gas emissions. We have to deal with the waste issue," he said.

In previous stops in Nevada, Richardson has described himself as "not a proponent" of nuclear energy. Asked Tuesday to clarify his position, the governor said he thinks "nuclear power is an option. I have felt that it doesn't emit greenhouse gas emissions. I'm not crusading against it."

As energy secretary during the Clinton administration, Richardson allowed the plan to store 77,000 tons of radioactive waste at Yucca Mountain to progress. He now says he's opposed to it because of safety concerns and wants to convert the facility to a laboratory to research nuclear waste disposal.

UA General President Bill Hite said he liked what he heard from Richardson and said energy issues would be central to the union's endorsement.

Hite said he would not endorse former Sen. John Edwards because of his opposition to nuclear energy.

Written By KATHLEEN HENNESSEY