(FORTUNE Magazine) – The Reagan Administration's apparent new willingness to force down the dollar and vigorously enforce U.S. laws against unfair trade has given congressional moderates a much needed counter to proposed protectionist legislation. And that, says Deputy Treasury Secretary Richard Darman, ''has reduced the overall threat of protectionism gaining veto-override strength.'' The bellwether vote will come soon over legislation to reduce import quotas on textiles and apparel by up to 40%. A week before Reagan's trade speech, Administration strategists doubted that they could muster the one-third vote of either house necessary to sustain a veto. But after the speech outlining a tough Administration trade offensive, support for the bill began to wane. Although the measure is still expected to pass both houses, congressional pulse-takers now agree it's highly unlikely that the bill's sponsors will have the votes to override a veto. Says U.S. Special Trade Representative Clayton Yeutter: ''If we prevail, I think a lot of other protectionist legislation will move to the back burner.'' For the moment at least, congressional attention seems to be shifting from import protection to broader legislation to promote exports and attack unfair trade practices. The key components of an emerging congressional package likely to win bipartisan support include: TOUGHER TRADE LAWS. Congress wants to limit the President's discretion in enforcing laws against unfair trade practices. Legislators want to give the U.S. Special Trade Representative greater authority and set tougher timetables. EXPORT SUBSIDIES. Legislators will want to increase the President's proposed $300-million export-financing war chest. The program proposed by the White House would enable the Administration to offer foreign buyers up to $1 billion in so-called mixed credits -- blends of government financing at near- commercial interest rates and foreign aid money at highly subsidized rates. TRADE ADJUSTMENT ASSISTANCE. Three days after the President's speech, the Senate Finance Committee passed a $250-million program, financed by a new 1% fee on imports, designed to retrain workers who have lost jobs because of foreign competition. Despite Administration objections, it's likely to become law. INTERNATIONAL MONETARY REFORM. Support is growing for an international conference to move toward a more controlled exchange rate system. Congressional and Administration strategists admit that even these measures will not shrink the trade deficit quickly. And they worry that as the 1986 congressional elections approach, the protectionist fires could blaze again. Says Richard Rahn, chief economist for the U.S. Chamber of Commerce: ''The danger is still real and present.''