At the center of the sometimes rancid and often overwrought debate about American foreign policy in Central America stands Rep. Dave McCurdy. He's a young (36) third-term Democrat from Oklahoma who some say is a bit presumptuous to be making like a secretary of state. But any port in a storm, I say, for a high-priority presidential policy that is foundering.

Last time around, in April, administration supporters in the House gleefully gambled on what looked like a clever parliamentary maneuver. The effect was to stall an effort by McCurdy and a bloc of centrist Democratic (and a few Republican) swing voters to stretch out and pare down the administration's program for $70 million in military aid and $30 million in "humanitarian" aid for Nicaraguan contras (a k a "freedom fighters"). The Great Communicator would then lead a lobbying campaign to turn congressional opinion around in the administration's favor.

But two months later we see a familiar anomaly. The president's two-to-one approval rating in the polls is matched by about the same balance of public opinion against contra aid. Most Americans are still not buying Ronald Reagan's forebodings of the awful consequences if the House does not match the Senate's approval of the president's program.

This week the House is scheduled to take a second whack at contra aid. Dave McCurdy is once again the point man in search of a compromise to resolve a struggle that the administration appparently has no better chance of winning than it did two months ago. But this time, there are significant differences. The administration insists that the need is urgent; Republicans can no longer stall.

Meanwhile, McCurdy, on behalf of the "swing voters," has been working with top House leaders on a two-pronged approach. His draft amendment would impose the same negative constraints and conditions on military aid as before. But it would add something new -- and positive.

McCurdy was one of a delegation of a dozen compromise seekers (nine Democrats and three Republicans) who recently returned from the region impressed by the fragile flowering of democracy in El Salvador and Guatemala, the somewhat deeper rooted democratic tendencies in Honduras, and the well-established freedoms in Costa Rica. So McCurdy and Co. would fall back and regroup. They would concentrate the biggest U.S. effort not on contra support but on shoring up these potential targets of Nicaragua's expansionist ambitions.

The administration can hardly dismiss the idea out of hand. What's proposed is a Central American economic aid program borrowed from the recommendations of Ronald Reagan's Kissinger Commission. Even the numbers, something in excess of $400 million over several years, are the same.

Now that the budget squeeze threatens to decimate U.S. foreign aid to all but a few favorites (notably Israel and Egypt), the predictable administration position would be that Congress couldn't find the money -- even if asked. But according to congressional sources, McCurdy has a ready reply: When the president talks about a "national security disaster" if the contras don't get their guns, he is talking as much about the province of the Defense Department as the concern of State or the foreign-aid agency.

So the idea would be, as one source put it, to "program the money out of the Pentagon." The theory is that the money would have to come from there in the end, if Ronald Reagan's most inflamed fears are realized and U.S. force is deemed necessary to stem the communist tide.

"By building up The Four," as one congressional aide put it, "we could show the peasants that democracy works." This presumably would strengthen resistance to communist subversion in El Salvador, Guatemala, Honduras and Costa Rica. There is also the "showcase" factor, which is as likely to create pressure for change in Nicaragua over time as anything that the contra forces could accomplish.

Regularly, the specter is raised of a powerful 60,000-man Nicaraguan army with 60,000 militiamen in reserve and high-tech Soviet weapons. Suddenly, reports are produced of yet one more shipment of Soviet military supplies to the Sandinistas. What the administration does not explain is what would stop the Soviets from yet another, and another, shipment of arms in response to the relatively modest military aid to the contras for which the president is pleading.

The issue is both enormously complex and relatively simple: If you believe that a counterrevolutionary insurgency that has been unable to seize and hold any territory for any length of time over a span of five years or more can be infused (for $100 million) with enough zeal and discipline to make the Sandinistas say "uncle," the United States might be morally obligated to help free the Nicaraguans from Sandinista repression.

But suppose you share the belief of most hard-headed experts -- that the government in Managua has consolidated its hold and will be impossible to dislodge by indigenous forces without much more military aid than the administration is asking for. In that case, there is something to be said for a greater effort to reinforce the second line of defense against communist expansion in Central America: those countries where democracy seems to be proving itself.