Al Gore hopes to put global warming back at the top of Washington’s agenda Thursday, but some Democrats in Congress are questioning his timing when they are getting pummeled by Republicans over record gas prices.

Gore hopes to deliver a major speech on the environment at Constitution Hall in Washington that will “press the reset button on how people are looking at the energy crisis and the climate crisis,” said Brian Hardwick, spokesman for Gore’s Alliance for Climate Protection.

The question some Democrats have is whether a high-profile speech about the importance of protecting the environment might be exploited by Republicans who want to portray their ideological opponents as caring more about polar bears than Americans who have had to pay record prices for gasoline.

“It depends on how it’s presented,” said Sen. Frank Lautenberg (D-N.J.), who emphasized he did not want to “pre-empt” Gore’s speech by telling him what to say.

“I think the American public will be much more receptive to arguments about climate change when gas prices aren’t so critical,” said Rep. Zack Space, a freshman Democrat who represents a mostly rural district in Ohio.

Space and other Democrats say that gas prices have begun to overwhelm other issues.

Republicans are pouncing on Gore’s re-emergence, holding it up as proof that Democrats favor environmental policies that further escalate energy costs.

“Mr. Gore will yet again call attention to the policies called for by radical environmentalists that would result in even higher gas prices,” said Michael Steel, spokesman for House Republican Leader John Boehner (Ohio).

Gore’s speech comes at a time when others are vying for the spotlight in the energy debate.

Prominent oilman T. Boone Pickens is also positioning himself at the forefront of the energy debate.

He has launched a national media campaign to advocate for wind energy with television and newspaper ads.