By any measure, ethanol is a $7 billion economic, environmental and energy-independence bust. Politically, however, the corn-based fuel additive is one tough piece of pork.

Just a few short weeks ago, everything seemed to be in place for Congress to scrap this 18-year-old boondoggle: Robert “Senator Ethanol” Dole was gone; environmentalists, economists and the General Accounting Office had pretty much agreed the additive wasn’t doing the job; it had become Exhibit A whenever corporate welfare was on trial; Texas Rep. Bill Archer, head of the all-powerful Ways and Means Committee, had it in his budget-cutting sights.

Then something went terribly wrong. Or, considering that this is Washington, something went as usual. When the dust settled from all the log-rolling, not only had Archer failed to kill the ethanol subsidy by the year 2000, he narrowly avoided seeing it extended for another seven years at a cost to taxpayers of another $3.8 billion.

Archer made a good fight of it, but it’s hard to stay in the ring against a tag team of President Clinton, Vice President Gore, Minority Leader Gephardt, Speaker Gingrich and just about every pol who hopes to get a vote out of the Farm Belt, all of whom love to pose in front of corn fields while declaring ethanol to be the greatest thing since soft money.

The ethanol subsidy was concocted in 1979 as a short-term aid to the development of a fuel additive that would free the nation from the Mideast oil tyrants and clean the air at the same time. Talk about a monumental dud: ethanol accounts for less than 1 percent of U.S. fuel consumption and it’s a notorious smog-producer in warm weather. Plus, it takes more energy to cook up a gallon of the stuff than that gallon turns out. Otherwise, it works great.

The worst thing about ethanol, though, isn’t the waste. It’s the perverse effect it has upon politics, especially presidential politics. The race for the White House has become a horse race and the Iowa caucuses are the first heat.

The way Iowans see it, those who are not on record as being truly, madly, deeply in love with ethanol need not bother to show up. Just ask Texas Sen. Phil Gramm. He was cool to ethanol in ’96 and got buried. Now, he’s back as an ethanol convert.

Then there’s Arizona Sen. John McCain, a man of considerable presidential timber. He said recently he’d like the job, but admitted he doesn’t stand a chance because he’s anti-ethanol and proud of it. And so the nation seems destined for another campaign cycle in which the front-runners will be chosen on the extent to which they embrace the useless product of a useless program.

Well, not totally useless. If we ever need a cure for convictions and principles, we know right where to find it.