While public attention is focused on violence and vote fraud in the Philippines, the administration is approaching a crossroads in the dirty little war in Nicaragua.

U.S. intelligence reports give a bleak picture of prospects for the Nicaraguan rebels, whom President Reagan refers to as "freedom fighters" and others call the contras.

According to these reports, only 8,000 rebel troops, one-third of the total force, remain active inside Nicaragua. In the last year, these soldiers have become hunted men whose supply lines are blocked by increasingly effective and well-armed Sandinista counterinsurgency units, aided by Cuban advisers. U.S. analysts say the Sandinistas are winning the war.

Against this backdrop House Minority Leader Robert H. Michel (R-Ill.) and Rep. Dick Cheney (R-Wyo.) last week sent President Reagan a letter asking him to seek substantial military aid for the rebels and an end to congressional restrictions "prohibiting CIA involvement with the freedom fighters."

The letter appealed to Reagan "to make a major personal commitment to the effort to explain to the American people why this course of action is necessary." Implicit was the suggestion that Reagan, for all his celebration of the Nicaraguan freedom fighters, was doing less than he should to arm them.

Last year, Michel and Cheney extracted a compromise from Congress providing $27 million in "humanitarian" aid to the rebels. At the time, it was widely believed that the rebels, if possessed of bedrolls and bandages from the United States, could buy enough arms on the open market to challenge the Sandinistas.

This hasn't happened. The rebels, most of them languishing in Honduran camps, have remained ill-equipped, poorly trained and badly armed. While a continuing minor annoyance to the Managua government, they also have served as an excuse for further Sandinista repressions and additional demands on Soviet-bloc nations for modern weapons.

In Washington, the rebels usually have been regarded as heroes by the right and bandits by the left. But the political consequences of their plight have not been evenly distributed. Democrats in the Southwest, where sentiment against the Sandinistas runs high, took themselves off the hook by supporting humanitarian aid. Those Republicans who would like to see the rebels become an effective fighting force have had to content themselves with Reagan rhetoric while the contras drift into obscurity.

Last week, in an interview with The Washington Post, Reagan was asked whether he would seek military aid or allow the "freedom fighters to wither on the vine." Before the question was finished, the president responded, "I'm going to go all out to try and get them the kind of aid they must have."

It may be instructive that he did not say "military aid," a phrase that has become code for overt assistance provided through the Defense Department, as favored by influential Senate Foreign Relations Committee Chairman Richard G. Lugar (R-Ind.). House Republican leaders prefer covert aid through the Central Intelligence Agency, a system that has the advantage of disguising the amount and the drawback of offending members of Congress who distrust the CIA more than they do the contras.

While the debate on how best to aid the contras rages, the rebels are losing their effectiveness as a fighting force, and Cheney and Michel want to make their potential demise a political issue. Their polite letter challenges the president to put his money where his mouth is and invest in the rebel cause some of the popularity his managers are hoarding.

"It is not in the national interest to pursue a policy that is doomed to fail on the grounds that it was all the Congress would allow," the two wrote. "If the communists and their Soviet-Cuban allies are going to be successful in Nicaragua, let the record show that it was the direct result of the unwillingness of Democratic members of Congress to support the administration's request for military assistance to the anticommunist insurgence."

Reaganism of the Week: Answering a question about technology at a luncheon of regional journalists last Monday, the president said: "I'm not technological gifted in that way. I haven't even been able to learn to use a pocket calculator yet."