Of the seven probable, possible or in-any-way-likely presidential candidates, only one of them has in the last week made a major statement concerning the U.S. involvement in El Salvador. That happened to be the man who is involving the United States in El Salvador--Ronald Reagan. Say what you will about him, he at least spoke up on the issue.

Not so the Democratic presidential candidates. Almost the entire mob of them has either been too busy or too timid to address an issue that is beginning to look more and more like Vietnam. It turns out that running for president also means running away from controversy.

It could be, of course, that somewhere on the hustings, in some kaffeeklatsch or speech to a PTA, one of the Democratic candidates unburdened himself on El Salvador. That is possible. But when it comes to making a full-fledged speech, when it comes to issuing the sort of policy statement that attracts the attention of the national press, not one of the Democrats could find either the time or the courage to do it.

The upshot is that the field has been virtually left to the one man unafraid to speak up, Reagan--and to his critics on the Hill. They are formidable, but they are not the heavyweights of the Democratic Party. Nevertheless, it's been up to the likes of Rep. Michael Barnes (D-Md.) to take on the president, to question whether the requested $60 million in military aid is going to buy us anything more than another quagmire.

But of the Democratic presidential candiates, only one even contested the president's assertion that as San Salvador goes, so goes Nutley, N.J. That was John Glenn, who is about to endanger his reputation for sticking safely to the middle of the road. He issued a press release saying that the requested $60 million "was vastly out of proportion with our interests and objectives in that country."

As for the others, nothing. Maybe this is because they all agree that El Salvador is really the linchpin of the Western Hemisphere. Doubtful. Maybe they all agree that a military solution is, in fact, a solution. Again, doubtful. Maybe it is because Ted Kennedy, who has spoken out, is no longer in the race and where he leads, they do not need to follow. Not so doubtful. Or maybe they are afraid of being called soft on communism. Not doubtful at all. In fact, that's probably the case.

Whatever the case, the United States is embarking on a serious foreign policy venture with precisely the sort of nondebate that led to Vietnam. Domino theories go unchallenged and the longstanding political and economic realities of a region are explained by saying that one side ours won't fight at night. Instead of questioning any of that, the Democratic candidates appear at cattle shows where they parade their speaking skills and then wait for the morning paper to find out who won.

But the obligation of a presidential candidate is not just to hit the red on an applause meter, but to raise and clarify issues. That is particularly the obligation of the front-runner, who commands the press attention that can by itself ensure a debate. Walter Mondale should be talking about El Salvador and not tap dancing for party and press--playing it safe to protect a lead that through timidity he will surely lose.

That might be an unfair shot at Mondale, but it comes with the territory of being the front-runner. In a different way, the same sort of criticism could be leveled at Gary Hart, who says he speaks for his generation but on this issue does his speaking with his mouth shut. The same could be said of Alan Cranston, who seeks the liberal vote but last week failed to challenge the president on El Salvador.

So at the moment, the field is left to the president. His domino theory goes unchallenged. His exaggerated anticommunism goes unquestioned and, as a result, he just might get his way on El Salvador. Years from now people may ask how that happened. They'll be told that the leading politicians neither had the time nor the guts to respond to the president. There was a campaign on.