Just in case you slept through it, the Reagan administration had a bipartisan policy for Central America the other day. It was beautiful: Henry Kissinger himself would guide a "blue ribbon" commission's search for a national consensus on how to handle communist encroachment in our hemisphere. And then, like a shooting star, it was gone.

The Kissinger commission will live on. But the bright flash of bipartisanship lasted only as long as it took Sen. Jesse Helms to write a confidential memo to his colleagues on the Senate Foreign Relations Committee, demanding urgent hearings.

Helms' witness list, in its entirety: Henry Kissinger; Seymour Hersh, author of a 640-page indictment of Kissinger's public service; and a professor Henry Paolucci, whose much slimmerr "Kissinger's War" makes Hersh look evenhanded.

"Jesse has a great sense of humor," said a Senate committee aide, who was not laughing. Helms is chairman of the Senate's Latin America subcommittee. He is also an ideological kissing cousin to a conservative coalition that is organizing its own watchdog commission to yap at Kissinger's. The membership constitutes a fair sample of Reagan's hard-core constituency.

If arousing the wrath of your own true believers is a dumb way to set out in search of consensus, even dumber is the way the administration went about building bridges to the opposition party (which is what bipartisanship means, if it means anything).

The Reagan way was instantly to make it known that his mind had already been made up and his means and methods selected, before he reached out to touch everyone. Accommodation with Nicaragua's Marxist junta is out. Gunboat diplomacy, with perhaps even a naval "quarantine," is in. So is a fight to the finish in El Salvador and an expanded military presence in the region.

The official leaks were torrential in their details. Five months of Central American war games on land and sea are only part of a "newly devised, long-range Reagan administration plan . . . hammered out during the last four weeks in inter-agency discussion," said an account in The Washington Post; military and economic aid in Central America would be increased by $400 million.

The president denied such firm plans; he would take away the White House passes of the leakers if he could find them. Apparently he couldn't find the "senior national security official" who turned up the next day in The New York Times hailing a "program for significant and long-lasting increases" in the U. S. military presence in Central America. More leaks told of plans for vast expansion of covert activities and even a license for U.S. military advisers to go on combat missions with the Salvadoran army.

If this is a bluff, it's a dangerous game. The gang that fought its way into power in Managua and then muscled out its moderate element will not be easily bluffed, and still less will its Soviet/Cuban patrons if their investment is anywhere near as large and their commitment anywhere near as absolute as the administration would have us believe.

If it's not a bluff, it's both dangerous and duplicitous. Sen. Robert Byrd, whose position as minority leader makes him someone you would want with you in any serious bipartisan effort, was not the only Democrat to sense "a smoke screen for the administration to get its way."

People with a post-Vietnam mindset would suspect duplicity. Generosity argues that some allowance be made for blinkered zeal and ignorance. When administration officials hold up the Marshall Plan as their model, they are either kidding us or themselves. The Marshall Plan was not a hard-and-fast proposal, but an invitation to the Europeans to take the initiative for their own salvation. Its "commissions," headed by men like Henry Stimson, Averell Harriman and Christian Herter, were charged with rallying support by talking to--and hearing--all sides.

Contrast that with an administration that spots Congress in the act of setting up a bipartisan commission, sends high- level scouts to Capitol Hill to find out what's going on, then co-opts the idea with a commission of its own--while rushing to put into practice its own policy. At some point, if the effect is what counts, it ceases to matter how much of this you credit to bad faith, and how much to incompetence.