In the presidential fight between Sens. Hillary Rodham Clinton of New York and Barack Obama of Illinois over a suspension of the federal gas tax — she’s pushing hard for it, he calls it a “gimmick” — Clinton may be left out in the cold by her own party.

When Senate Democrats unveil an energy package later this week, it is not expected to contain a gas tax holiday, said a Senate Democratic aide. “It’s a nothing burger. It’s not even part of the discussions,” the aide said.

To be sure, soaring gas prices and election year urgency have lawmakers tossing out a grab bag of proposals to ease pain at the pump — but the tax holiday hasn’t shown up anywhere, including in Democrats’ own proposals.

And it was absent from a package of Senate Republican proposals unveiled last week — even though presumed Republican presidential nominee John McCain of Arizona supports it.

Lawmakers say that’s less indicative of candidate endorsements than it is a reflection of the criticism the proposal has drawn. Many economists, including at least four Nobel Prize winners, have called it bad economic policy.