WASHINGTON -- The first caucuses of the 2008 presidential campaign are more than two years in the distance, but Iowa's interest in ethanol knows no season.
That may help explain why Senator John F. Kerry, Democrat of Massachuetts, nearly alone among senators from the Northeast, voted recently to fend off an attack on government support for the corn-based fuel alternative.
And why Senator George Allen cast a similar vote, marking a turnabout in his position. It left him on the opposite side from Virginia's other Republican senator, John Warner.
''It doesn't require presidential ambitions for United States senators to want an energy policy that benefits consumers and relies on American farmers, not the Saudi royal family," said David Wade, a spokesman for Kerry, the Democratic presidential candidate last year and a potential contender in 2008.
A spokesman for Allen, a possible White House challenger in 2008, said, ''Virginia is looking for ways to transition from traditional crops."
David Snepp also pointed out that the same provision in the bill expands federal support for fuel derived from crops other than corn. On May 16, Allen and President Bush toured a West Point, Va., facility that produces biodiesel from soybeans.
Turning the Senate into a springboard to the White House is a recurring ambition, last fulfilled by John F. Kennedy in 1960.
Still, hope is as fertile as Iowa farmland.
Energy legislation customarily underscores regional rather than party differences in the Senate. But presidential ambition also poked through during last week's debate.
Corn is abundant in Iowa, where it is processed into ethanol in increasingly larger amounts. Iowa also stages party caucuses every four years that provide the first major campaign test of the presidential campaign.
Ethanol ''is certainly an issue that comes to the forefront very early on in the caucus process, whether because there are Iowans out there asking the candidates or the Iowa media are asking," said Eric Woolson, a spokesman for the Iowa Republican Party.
''It's just the first question on everyone's mind," agreed Jeff Link, a Democratic strategist who lives in Iowa.
He spoke of farmers who are getting together to put up money to build ethanol plants ''because this is seen as a way to assure a vibrant economy."
In the past, Kerry has supported alternative energy sources, including ethanol, although his stance differs sharply from most senators from the Northeast.
Of the 18 senators from six New England states plus New York, Pennsylvania, and New Jersey, only Kerry and Senator Judd Gregg, Republican of New Hampshire, sided with ethanol on the important vote.
Fifteen senators voted the other way, including Edward M. Kennedy of Massachusetts. Senator James Jeffords, Independent of Vermont, did not vote.
Among other potential presidential contenders, Senate majority leader Bill Frist, Republican of Tennessee, voted to protect the expanded mandate, as did Senators Sam Brownback, Republican of Kansas; Chuck Hagel, Republican of Nebraska; and Evan Bayh, Democrat of Indiana. All are from states where corn is grown.
Senator John McCain, Republican of Arizona, voted with ethanol's critics, as he has before.
Senator Hillary Rodham Clinton, Democrat of New York, and Rick Santorum, Republican of Pennsylvania, also voted against the wishes of ethanol supporters. Both are seeking new Senate terms in 2006.
Allen, too, is juggling the demands of a Virginia reelection campaign in 2006 and a possible run for the White House in 2008, but he voted for greater ethanol use. Two years ago, he opposed an effort by Frist, another 2008 presidential hopeful, to increase the amount of ethanol or other alternative renewable fuels.
Allen's spokesman, Snepp, acknowledged that this year's vote amounted to a change in position for the senator. But Snepp said it resulted from changing technology, rather than politics.
Allen ''believes that advances in technology have made production of energy and other biofuels more economic and beneficial for regions of America that produce agricultural crops like corn, but that also includes Virginia, because it gets into the whole debate over soybean diesel," Snepp said.
Unlike Kerry, who does not face his home-state voters next year, Allen remains coy about the possibility that he might run for the White House. He is scheduled to travel next weekend to New Hampshire, the state that will hold the first-in-the-nation presidential primary in 2008.