Muckraker: Grist on PoliticsThe “gas tax holiday” has officially emerged as the latest bickerfest big issue in the presidential race. Hillary Clinton and John McCain say drivers need a break this summer, while Obama is aggressively pushing back against the idea.

In a new ad, Obama emphasizes that cutting the tax this summer would save most consumers a mere $30 — about half the cost of a tank of gas these days. It’s a short-term fix, he says in the ad, and “that’s typical of how Washington works.” (Even McCain has acknowledged that the holiday would amount to only a “psychological boost” and not sound policy.) Instead of gimmicks, Obama notes in the ad that we need to raise fuel efficiency and develop alternative fuels as a solution to gas woes. He’s been pushing alternative transportation systems like rail transit, as David noted.

Obama’s stance is backed by economic experts, virtually none of whom think a gas-tax holiday is a good idea. Most environmentalists are also opposed, and in recent days some leading Democrats, including House Speaker Nancy Pelosi (D-Calif.) and House Majority Leader Steny Hoyer (D-Md.), have also come out against the proposal.

But Obama’s going to have trouble defending his position. His opponents are painting him as unwilling to help out cash-strapped average Americans. And some fellow Dems are joining calls to repeal the tax, among them Sen. Bernie Sanders (D-Vt.) — generally among the more environmentally concerned senators — who voiced support for axing the tax today. He suggests doing it in conjunction with an excise tax on oil companies:

The $35 billion in new revenue would fund a six-month federal and state “gas tax holiday.” This approach would lower the price of gas by up to 36 cents a gallon without reducing the Highway Trust Fund at a time when repairs to our decaying roads and bridges are desperately needed.

Of course, Congress could just instate that excise tax on oil companies without the gas-tax holiday and put that $35 billion toward long-term solutions.

As Memorial Day draws nigh and congressional representatives start taking sides on this issue, you can be sure the “gas tax holiday” will be a hot one in weeks to come.