A gasoline additive responsible for contaminating groundwater in communities across the nation could hamper the White House ambitions of a handful of Republican Senators who support liability protection for its manufacturers.

New Hampshire political observers warn that support for a federal liability shield for producers of methyl tertiary butyl ether in any energy bill produced by Congress is likely to hurt would-be presidential candidates in the eyes of Granite State voters.

“I think it will play big time in New Hampshire,” said state Sen. Robert Letourneau (R-N.H.). “Anybody interested in running for president in the primary and supports [liability protection], if it doesn’t completely sink them it will damage them.”

New Hampshire’s first-in-the-nation presidential primary is one of the most important proving grounds in what has increasingly become a short sprint toward the presidential nomination.

Mark Wrighton, an assistant professor of political science at the University of New Hampshire, said voters are certain to quiz White House aspirants about why they supported liability protection for MTBE manufacturers if it is part of the final energy bill.

“I think candidates will be asked about it in New Hampshire and how they respond may determine how individual voters cast their ballots in the primary,” he said. “One thing about New Hampshire voters, they are politically savvy.”

Congress is expected to address the MTBE issue in the coming months, when House and Senate negotiators try to reach agreement on a bill to overhaul the nation’s energy policy. The House has already approved an energy bill that includes liability protection for MTBE producers. The Senate may begin considering its bill as early as next week, but it does not contain liability protection language.

Senate Energy and Natural Resources Chairman Pete Domenici (R-N.M.) acknowledged at a May 26 news conference the MTBE provision could be a hurdle in the goal of reaching agreement on an energy bill this year.

“Everybody knows that it is a real sticking, to say the least, issue for the United States Senate, a real stumbling block,” Domenici said. “So we are committed to work with the House, work with the White House, to come up with a solution that the United States House can accept.”

House Majority Leader Tom DeLay (R-Texas) is adamant that liability protection for MTBE manufacturers be part of the energy bill. New Hampshire’s two GOP Senators oppose the measure and have said they would again try to block it from being enacted. Sen. Charles Schumer (D-N.Y.) has vowed to filibuster an energy bill that contains the liability protection provision.

Senate Majority Leader Bill Frist’s (R-Tenn.) spokeswoman said he is in frequent contact with the New Hampshire Senators about the issue “and he is hopeful that the House and Senate will be able to craft a compromise that will allow the energy bill to be sent to the president and signed into law.”

Amy Call, the spokeswoman, did not say whether Frist, who is taking preliminary steps to run for president, would support an energy bill with that provision.

MTBE is an additive that is designed to help gasoline burn more cleanly. But when it leaks from storage tanks, the possible carcinogen moves quickly toward water and is responsible for contaminating water supplies in the Granite State. New Hampshire lawmakers believe that it is such a problem, the governor recently signed a bill into law that will ban its use in the state beginning in 2007.

Sen. John Sununu (R-N.H.) said his state’s voters will expect answers from potential candidates on the issue.

“Contamination has been found to be a big problem in a number of areas across the state and even the average citizens who are not in public policy positions are very sensitive” about MTBE, he said. “I think anytime they have a chance to talk with or question someone who is working in Washington, D.C., they are going to expect them to understand the issue and to be responsive.”

Still, several Republican Senators mentioned as potential presidential candidates said they would support an energy bill with an MTBE provision despite New Hampshire voters’ opposition.

“I know the people of New Hampshire have a problem and I understand the problem and I think the responsible parties should take care of it,” said Sen. Rick Santorum (R-Pa.). “But I don’t think the manufacturers are the problem here. It is the parties who are liable for this material getting into the groundwater who should be held responsible. Not folks who manufacture a safe, legal product.”

Sen. George Allen (R-Va.) echoed Santorum’s assessment and emphatically said he doesn’t “mind, obviously, the idea of giving them immunity from accidents they didn’t cause.”

Allen said there is a greater need for the U.S. to put in place a new energy plan.

“I want to get an energy policy so we are less dependent on foreign oil,” Allen said. “The overall bill is the most important bill for jobs, security, competition and competitiveness. That is my main goal.”

Sen. Chuck Hagel (R-Neb.), through a spokesman, said he would support an energy bill if it included an MTBE provision. Hagel’s close political ally, Sen. John McCain (R-Ariz.), breaks with his GOP colleagues on this issue. McCain said in no uncertain terms he would oppose any bill containing a liability shield for MTBE manufacturers.

“It is outrageous,” said McCain, who won the New Hampshire presidential primary in his unsuccessful bid for the White House in 2000. “That is disgraceful … it is a terrible idea.”

State Rep. James Phinizy (D-N.H.), a co-author of the bill banning MTBE’s use in the state, predicted that a presidential candidate’s support for liability protection “would be a mark against them” with New Hampshire voters.

“What people in New Hampshire are tired of is about every four years turning around and saying we need your approval therefore we are going to come up and pander to you,” he said. “After that we are going to ignore you.”

Warren Henderson, chairman of the New Hampshire Republican State Committee, cautioned that it is difficult to predict what issue will be of overriding concern three years from now.

“It has been an issue that has caused grave concern in New Hampshire and will continue to do so,” said Henderson. “That is just a fact.”

But Henderson added, “By the time the primary rolls around it is hard for me to believe that one issue in and of itself would make or break a presidential candidate unless it represented some sort of pattern of systematic insensitivity to consumers, the region or the environment.”

Andy Smith, director of the University of New Hampshire Survey Center, said a candidate’s position on the economy and the war are more on the minds of New Hampshire voters. But Smith noted MTBE will be considered by primary voters.

“I think it is going to be an difficult issue to win or lose votes on,” Smith said. “But I think it is the kind of issue to help define a candidate.”

The MTBE issue is not likely to play a role in the New Hampshire Democratic primary, because all of these Senators have said they oppose liability protection for the manufacturers.

“It is wrong,” said Sen. Hillary Rodham Clinton (D-N.Y.). “We have all these municipalities in New York that are going to have to spend literally billions of dollars to clear up our water supply. I am sure there could be something if people were willing to negotiate in good faith that we could work out to give us some help. But absolute waiver from liability like Tom DeLay is insisting on is unacceptable.”