HOW CAN IT BE that this great and free nation is still debating whether to ape the dictatorships of the world and apply a political standard in determining which foreigners should be allowed to visit this country? Through the cold-war years American law applied just such a test. There was a list of politically proscribed organizations, including communist parties, and individuals belonging to them needed a waiver in order to be let in-the presumption of the law was that they should not be.

The law was amended two years ago to make it less cumbersome and-no small consideration-more dignified for such foreigners to enter. In effect the presumption was reversed. This was done in the "McGovern amendment," a worthy measure passed specifically to make American visa regulations consistent with the traditional free-travel principles the United States was championing in the Helsinki Accords.

But a relapse now threatens. Urged on by the American-Israel Public Affairs Committee, which wishes to keep out members of the Palestine Liberation Organization, the House voted two weeks ago to deny the courtesies of the McGovern amendment to anyone in the PLO.AIPAC struck for this change at a moment when diplomats are circling warily around the Palestinian question in the Mideast peace talks. It wants to pin the "terrorist" tag on all branches and members of the PLO, regardless of their particular records or views.

This week an effort is expected on the Senate floor to repeal the whole McGovern amendment. AIPAC can be counted on to be in there pitching, along with the AFL-CIO, which has long nursed a grudge against travel here by communist trade unionists and which was responsible for Senate passage of a repealer last year. The House did not go along.

The issue is clear. A country that believes in free travel should make it as easy and orderly as possible for foreigners to come in. It is a way to show respect for American principles, to gain the advantages of contact with people who have other ideas and points of view and to improve the prospects for persuading other nations to open their gates wider. There is no question here of admitting people who are simply terrorists or who are otherwise regarded as inimical to legitimate American interests. Other provisions of the immigration law assure the authorities adequate controls over them. It is a question of access for people who hold different political views.