WITHOUT WAITING for the Panamanian equivalent of the farm vote to roll in, it seems safe to hail the apparent 2-to-1 majority for the canal treaties in Panama's plebiscite on Sunday for what it largely is: the removal of the next-to-last obstacle blocking the resolution of the Panama Canal issue. The last obstacle, of course - and the only one of any consequence since the final agreement on the treaty language - is the plebiscite that will be held in the U.S. Senate. There was never any doubt that the authoritarian government of Gen. Omar Torrijos could muster a majority vote for the treaties. For all the opportunity he offered for some restrained expression of dissenting opinion and for all the evidence of honest voting procedures overseen by foreign observers, only the size of the margin was ever in doubt.

If there is any element of surprise in the outcome, it lies in the unexpectedly high level of opposition. Gen. Torrijos was predicting a 9-to-1 ratio and working toward that end presumably on the theory that an overwhelming majority would bolster his own standing while putting more pressure on the U.S. Senate where, it need scarcely be noted, the prospects for the necessary two-thirds majority are very much in doubt.

Frankly, we prefer the look of the actual outcome, if only because it suggests a more open test of public opinion and a genuine division among Panamanians about the treaties' terms. In all logic, if as many as one-third of Panama's voters are against the deal, this ought to suggest to its opponents in this country that as a practical political matter it may not be quite the giveaway that they would have us believe. We do not mean by this that the U.S.-Panamanian agreement automatically becomes a good deal for the United States just because large numbers of Panamanians apparently believe it to be a bad deal for them. What the vote does seem to confirm, however, is what a succession of American negotiators, under six Presidents, have been arguing all along: that there is a powerful and potentially explosive strain of nationalistic sentiment in Panama; that it finds expression almost wholly in strong and growing public resentment of the status quo regarding U.S. "occupation" of the Canal Zone and U.S. operation of the canal; and that this is a serious and growing problem, not just for the Panamanian government of the moment, but for the U.S. government as well.

If that is a reasonable reading of the outcome of the Panamanian plebiscite, it seems to us to buttress what we have always thought to be the strongest case for the new treaties - the case that rests, however hypothetically, on what would happen if the treaties are rejected and we simply stand on the status quo. The argument of the treaties' supporters is that Panamanian frustration would grow, and ultimately explode in riots or sabotage of the canal or a violent change of government, and that one way or another this might oblige the United States to intervene with its own troops - and under the terms of a 74-year old treaty that is respected by almost no other country in the world.

Opponents, of course, argue equally hypothetically that the same threat would exist under the new treaties - and so it might. But the difference, of course, is that in that case the Panamanian government would share responsibility for keeping the canal open with its own security forces, and the United States would have a clear, newly negotiated right - expressly confirmed in the recent joint interpretation of the treaties by President Carter and Gen. Torrijos, and accepted in the hemisphere and elsewhere - to act if the Panamanians could not or would not protect the canal. As we have noted more than once in this space, that strikes us a far sounder position from which to deal with the considerable undercurrent of nationalism and anti-Americanism revealed in Sunday's plebiscite in Panama.