Senator Barack Obama says if he's elected President, Al Gore will play a "major role" in his administration.

Obama said he would tap Gore to lead the charge against global warming.

Gore has not endorsed Obama or Clinton.

But another endorsement has the Clinton camp steaming.

New Mexico Governor Bill Richardson threw his support behind Obama late last month. Former President Bill Clinton considers that a slap in the face.

He says Richardson told him five times that he would not endorse Obama.

Every little bit of support counts in the ever-tightening Democratic race.

Polls show Clinton's lead shrinking in Pennsylvania 50-to-41. That nine point margin is nearly half what it was back in February.