JESSE JACKSON is still running vigorously for the presidency of the United States, but let it be noted that he is running only nominally against Michael Dukakis. Once in a while he will point up some place where he thinks the Massachusetts governor is not as strong as he should be, in the Jackson view. But it is perfectly clear that he is not running divisively. He is not hurting the party. He is saying nothing that the Republicans will be able to use against Mr. Dukakis in the final campaign.
And that makes a second respect in which the Jackson campaign is a big, big plus for Michael Dukakis.
It is perfectly obvious that the George Bush campaign is being geared to the familiar Republican strategy of portraying the Democratic candidate as being just another tax and spend ``liberal'' Democrat.
By current American political definitions Dukakis is more liberal than conservative. But he is less liberal, by a wide margin, than the Rev. Mr. Jesse Jackson.
Every time Jackson preaches more federal spending for day care, health care, education, and any other program aimed to help the poorer sections of the community, he makes Dukakis look more and more like a moderate, middle-of-the-road candidate.
The Jackson campaign is a lightning rod. It draws the antiliberal fire in his direction and gives Dukakis more room to present himself as the efficient public administrator interested in what works, not in doctrine.
Add a little side bonus in this for the Dukakis camp. The fact that Jesse Jackson is still campaigning, and still building an impressive battalion of delegates for the convention, keeps the story of the Democrats in the news, to Dukakis's advantage.
Against that, George Bush last week obtained the less than wildly enthusiastic endorsement of Ronald Reagan at a moment when Donald Regan's astrological revelations made even a halfhearted endorsement less worth having.
I have been covering and writing about American presidential politics since Franklin Delano Roosevelt trounced Herbert Hoover in 1932. I cannot recall any case since then when a presidency in its last year has been falling apart the way this one is.
The campaign against Daniel Ortega in Nicaragua has collapsed. Nothing the White House can do seems able to topple General Noriega in Panama. There seems to be no end in sight to more ``kiss-and-tell'' books from ex-Reaganauts.
And last week the big banks began to raise interest rates, a sure sign that the bankers think the economy is too near for comfort to the edge of a revival of inflation.
The condition of the economy is the centerpiece of the Reagan presidency. Seldom in history have so many been living so well and been spending so freely as Americans have over the past seven years or so.
If that condition holds, then Mr. Bush will face the voters on election day with his feet still planted on remarkable prosperity, or the appearance thereof.
But if anything unpleasant were to undermine the appearance of that prosperity between now and election day, we would have a decidedly different picture.
Granted, Mr. Reagan has presided over a remarkable reconciliation with the Soviets, which will be ceremonialized by Reagan's trip to Moscow before this month is out. The ceremony will probably be justified by ratification of the INF Treaty in the Senate in time for a celebration party in the Kremlin's great banquet hall.
But not since the last year of the unfortunate Hoover presidency has there been such a sense of an administration coming apart at the seams.
Until last week I assumed that the odds were still in favor of a Bush win in November. Certainly by now Dukakis has at least a 50-50 chance of winning.
Do you suppose Gov. Mario Cuomo of New York is beginning to think he made a mistake in keeping out of the race this year?