It is common knowledge among cautious conversationalists that politics makes a risky subject. Some people are discovering that it becomes only a little less dangerous when mixed with sports.
Ira Glasser, executive director of the American Civil Liberties Union, nearly became a persecution case himself when he wrote what he took to be a lighthearted little essay on ''The Baseball Guide to Character and Politics.'' Harking back to his Brooklyn boyhood of the late '40s, Mr. Glasser delivered a heartfelt, if predictable, tribute to the memory of Ebbets Field and the Dodgers when they were Brooklyn Dodgers and not Los Angeles suburbanites. Here, 26 years too late, was still another cry from the vanished bleachers of Flatbush: ''Bring back da bums!''
Such sobs - punctuated by anecdotes about the so-called Daffiness Boys - are as much a part of Americana as Casey Stengel, who used to lose with the Brooklyn Dodgers long before he won with the New York Yankees.
It is also considered edifying form to top off a Dodger elegy with the reminder that a Brooklyn uniform decorated the first black in major league baseball - Jackie Robinson. An executive director of the ACLU could do no less.
So far, so good. But then, after taking this modest lead off first into the metaphorical territory of politics, Mr. Glasser suddenly decided he could steal second, if not third - just like Jackie.
With reckless abandon, he divided all of New York baseball into three political parties. Yankee fans, he insisted, have always been ultra-conservatives, in love (if you can call it that) with a ''cold, remote, unfeeling corporate enterprise.'' Brooklyn Dodger fans, on the other hand, were ''egalitarians,'' rich in ''human values.'' New York Giant fans - watching their heroes at the Polo Grounds in those old pre-San Francisco days - were politically lost somewhere between Ebbets Field and ''The House That Ruth Built'': ''basically confused,'' victims of the ''moral schizophrenia'' of the ''ambiguous liberal.''
Well, sir! We took our seventh-inning stretch, so to speak and waited. A little later the New York Times dug itself out from under the mail with all the dignity of an umpire dusting himelf off after an assault by Billy Martin. ''Dodger Fan Is Called Off Base and the Wall'' read the headline above the letters to the editor.
One veteran Yankee fan, recalling his own baseball boyhood, observed: ''We lived in tenements in a lower-middle-class section of the Bronx. We did not know our fathers were tycoons masquerading as tailors and factory workers.''
An old Giant fan chose to ''brush off'' Mr. Glasser's ''snide comments'' by ''simply savoring'' once more Bobby Thomson's pennant-winning home run off Brooklyn Dodger Ralph Branca in 1951.
One quiet note was sounded above the fray: ''When you look at baseball and see social situations,'' a sky-view philosopher wrote, ''you're not a true fan. It's akin to claiming to be a gourmet and wondering what the dish washer is earning.''
These statesmanlike words were printed too late, alas, for Rep. Jack Kemp, Republican of New York. The same week Mr. Glasser started his three-bleachers rumble, Congressman Kemp mixed his sports with politics on the floor of the House. Commenting on a resolution that the United States should bid for the World Cup soccer matches, the former quarterback of the Buffalo Bills suggested that soccer is a cultural expression of European socialism. In less time than it takes for a quick count, other congressmen and the press were blitzing the old signal-caller.
Anybody wanting to be chased by the Glasser-Kemp mob can now speculate on how badminton expresses limited monarchy or analyze the Red Sox as a case of Boston Brahminism. Not us. Nevertheless, it must be said that sports are no longer just plain sports. Definitions of free agent are worthy of the business page. Explanations of the curve ball could fill a science-and-technology section. So why not sports and politics, or even politics and sports?
Wasn't it a brilliant political observer, Murray Kempton, who made a statement on New York baseball fundamentally in agreement with Mr. Glasser? More than 20 years ago he wrote: ''The New York of the Giants, Dodgers, and Yankees was an annual re-evocation of the War between the States. The Yankees were the North, if you could conceive a North grinding along with wealth and weight and without the excuse of Lincoln. The Giants and Dodgers were the Confederacy, often undermanned and underequipped. You went to Yankee stadium if you were the kind of man who enjoyed yelling for Grant at Richmond; you went to the National League park to see Pickett's charge.''
Now that's what we call sports writing.