HE SAT DOWN, THIS BIG guy with hairy arms, and he said he would play for awhile. We said fine, because he was a father and we were kids and back then you did not say no to fathers. This was the poker game at Stewie's house, a nickle-dime affair in the kitchen, the players being something like 15 years old, the father being, of course, a lot older and a lot richer. That was the important part - the money he had. When he sat down to play, he changed the rules.

He reached into his pocket and took out his money and it was more money than any of us had. He had real money, grown-up money, money from a supermarket and a laundromat and an interest, it was said, in a nursing home. We had kid money - allowance money, working-after-school money. It wasn't fair. There was no way to bluff him out. He would simply laugh and raise the stakes and stay in when he should have gotten out. He beat me and he took my money and it's a bitter feeling I will never forget.

It was a long time ago, but recently I think I have ssen that feeling written on the faces of some political candidates - the ones who are running against men of great wealth. They are quick to say that money cannot buy an election and quick to turn the issue to their advantage but the truth is that money can make all the difference. This is especially true now that almost no one can spend large amounts of money on campaigns for federal office but the candidate himself.

As a result, we have something new in American politics - the candidate with a constituency of only himself. The word constituency is used loosely here, but consider for a moment that Robert Short, the Democratic senatorial nominee in Minnesota, has lent his campaign committee $996,760, or 91 percent of its total receipts. With the Short campaign, at least when you are talking about money, there is almost no one else.

Unfortunately, Short is somewhat typical. In Virginia, for instance, John Warner accounts for 66 percent of the money that he has raised so far - $812,000, according to his financial reports. Warner, like Short, is something of his own creation, a man of wealth who went from private citizen to senatorial nominee, financing the entire voyage almost single-handedly.

There are others. In Illinois, Chicago lawyer Alex Seith, a Democrat, has the unswerving loyalty of his wealthy wife if no one else and has spent something like $600,000 on his campaign. That accounts for 83.7 percent of his total receipts. Just to balance matters, Charles Percy, the Republican incumbent, has put $475,000 of his money into his campaign.

And in Texas, in a race for the governor's mansion, William P. Clements, a man with a not-modest view of himself, has already spent $6 million on his campaign. Governor's races are not federal elections but a man who spends that kind of money on himself ought to be mentioned. In the same vein I would like to mention the Florida gubernatorial campaign between Jack Eckerd and Robert Graham. Eckerd has spent $2 million on Eckerd and Graham has spent $700,000 on Graham and closer to home in Maryland, Blair Lee III, spent $250,000, losing both the election and his money.

No one intends for things to work out this way. The idea from the start was to have a law that would put a ceiling on all contributions, including those made by the candidate himself. In the old days, in fact, there was a ceiling that applied to candidates, but then Congress passed a reform law in 1974. The Supreme Court struck down the provision applying to the candidates themselves, creating a situation where the biggest fat cat around is the candidate himself. In 1976, for instance, Sen. John Heinz of Pennsylvania lent his campaign $2.4 million and has never been paid back. Maybe he could sue himself and then reposses his car in the middle of the night.

If you take this law and combine it with another piece of reform legislation that limits senators to approximately $8,000 in outside income but excludes stock dividends or income from familyowned businesses, you have a situation where only the rich can play the game. You not only cannot make money while serving in the Senate, you can't even get there until you have some money. Already there are something like 23 millionaires in the Senate, about what there was, probably, when a direct election of senators was suggested as a way to democratize that body. We may have come full circle.

The point here is not that there is something wrong with being rich or that the rich don't belong in politics. The point, instead, is that they should be made to play by the same rules as everyone else or the rules should be changed so that others can play. Maybe government financing of campaigns would do the trick or maybe we ought to rethink the notion that money is the root of all evil. It shouldn't really matter where the money comes from as long as it's no secret - as long as it's disclosed. As it is now, politics is becoming like that poker game at Stewie's house. In theory, anyone can play.

But only the rich can win.