In early 1978 President Carter was pushing for ratification of the treaty he had negotiated with the Republic of Panama over the ultimate ownership of the Panama Canal.
The purpose of the exercise was to undercut and neutralize the routine Soviet propaganda argument that Uncle Sam is the exploiter of Latin Americans and is their enemy, not their friend.
The old situation in Panama was the ownership by the United States of a strip of territory running across the Isthmus of Panama and bisecting the republic. In that strip known as the Canal Zone white Americans were accustomed to the kind of preferential status over less white ''natives'' such as that European colonialists were accustomed to enjoy throughout the 19th century in Asia and Africa.
In the Canal Zone in the old times established by Teddy Roosevelt (and enjoyed by the beneficiaries) whites were paid in gold but ''natives'' in silver. Other appropriate differences separated the elect from their inferiors. It was a condition accepted generally during the 19th century, although sometimes resented by the natives. (The ''Black Hole of Calcutta'' was an incident of such occasional resentment.)
The idea of Euro-Americans being entitled to superior treatment failed to make the journey from the pre-1914 world into the post-1945 world. Colonialism became a bad word. The 19th-century empires collapsed. The Dutch, the French, the Portuguese, and the British hauled down their far-flung flags and went home. The Americans moved with the times. They, too, took down their flag from Cuba and the Philippines. But they hung onto their special privileges in the Panama Canal Zone until 1978.
Mr. Carter at the urging of the State Department worked out a new arrangement with Panama under which the US would retain de facto military control but give up the appearance and trappings of ''sovereignty'' at once - and turn the canal over to the Panamanians in 1999.
It was not popular in the US. Most polls showed public opinion about evenly divided, but with the advantage to the opposition. A New York Times/CBS poll taken at the peak of the debate in January showed 49 percent in favor to 51 percent against. One Gallup poll showed it the other way around with 45 percent in favor to 42 percent against. But it was narrow, and the opposition was lively.
President Carter's strongest argument which he used to the full on the Senate was that rejection of the treaty would cripple the President in his conduct of foreign policy. He asked Republicans to support him on this ground.
Ronald Reagan of California, a candidate for the Republican nomination in 1976 and in the lists for another try in 1980, joined the fray and became the most popular and vivid of the political opponents of the treaty. He argued that if the US gave up its ''rights of sovereignty'' over the canal it could be a first step toward ''loss of our freedom.''
Mr. Reagan in 1978 had little consideration for the idea of the effectiveness of the presidential office in the conduct of foreign policy. His anti-canal treaty speech went down well throughout the Southwest and particularly at American Legion and other patriotic organization meetings. It helped him to get nominated and elected in 1980.
Last week in Washington President Ronald Reagan urged both Republicans and Democrats to support him over the sale of American AWACS planes and other modern weapons to Saudi Arabia. His strongest argument was that rejection of the sale would cripple the presidency in the conduct of foreign policy. He was supported in this project by all of his living predecessors, Richard Nixon, Gerald Ford, and Jimmy Carter. Mr. Carter was not holding a grudge.
But the leader of the Democrats in the Senate, Robert Byrd of West Virginia, felt under no obligation to go along. Nor did most of the other Democrats in the Senate. If Mr. Reagan had felt free to brush aside the argument of the importance of sustaining the presidency in foreign policy during the Panama treaty fight, should they be bound by it in this fight in 1981? Besides, Democrats lost many Jewish voters to Mr. Reagan in 1981. Here was an ideal chance to win some of them back to their customary allegiance to the Democrats.
In theory in the US politics end at the water's edge.
The theory did not help Mr. Carter with Mr. Reagan in 1978.
It did not impress the Senate Democrats last Wednesday when the vote came on the AWACS deal. They voted 36-11 against Mr. Reagan.
Would the story have been different had Mr. Reagan in 1978 believed in the importance of sustaining the presidency in foreign policy matters?
P.S. Since becoming President, Mr. Reagan has had nothing further to say about the Panama Canal Treaty.