DENVER -- Speaker of the House Nancy Pelosi is urging the presidential superdelegates to make their picks as soon as possible.

She also had some good news for Sen. Barack Obama.

Pelosi believes the superdelegates should vote for the presidential candidate who has done the best in the presidential primaries and caucuses.

Obama is ahead in both the popular vote and number of elected delegates.

Pelosi told reporters that if the superdelegates override the will of the voters, there will be a voter backlash in the November general election.

Pelosi was in Denver Monday for a walk through of the Pepsi Center with Colorado Gov. Bill Ritter and Denver Mayor John Hickenlooper.

Democrats want to make this summer’s convention the most environmentally friendly ever.

The California Democrat and convention chair complimented efforts in Denver and across Colorado to push environmentally sustainable energy use.

"Energy security is a national security issue," Pelosi told reporters at the Pepsi Center, site of the convention. "It is an environmental issue, a health issue ... and it is a moral responsibility. We believe that this planet is God's creation, and we have a moral responsibility to protect it and this initiative does just that."

The committee organizing the convention has pledged to hold the most environmentally sustainable party convention in history. The group has a "director of greening" who previously monitored sustainability for Al Gore's concert series Live Aid. The committee also was the driving force behind owners at the Pepsi Center deciding to offset the energy it uses in a year.

Recalling her own experience organizing the 1984 Democratic convention, Pelosi said she was impressed the committee has found time to work on sustainability.

"It's a pretty exciting day," she said. "I have never seen a convention where the values of the American people have been the overarching concern" for the convention.

Hickenlooper and Ritter each stressed that the sustainability efforts were not just a publicity stunt.

"It's not about the PR," Hickenlooper said. "What we are doing is creating a legacy for the city of Denver that will bring benefit to our businesses and our citizens long after the convention has left."

Ritter said the initiative goes beyond politics.

"It's a statement of great substance that is about the future of this country," he said. "It's not a political statement when the Pepsi Center -- when Kroenke Sports (owner of the Pepsi Center and owned by reliable Republican contributor Stan Kroenke) -- when they look at this and say we want to be the first sports facility in the United States of America to be fully green. They understand that that is the way we must think about the future."

Convention committee CEO Leah Daughtry said Monday's announcement was one in a series of initiatives the committee plans to launch this month before Earth Day on April 22.