Like most politicians, President Peter O'Malley of the Washington Capitals is a boundless optimist. So when O'Malley declares flatly that the Capitals will participate in the Stanley Cup playoffs this spring one must judge accordingly.

"We will be in the playoffs," O'Malley said. "I couldn't have said that with a straight face last year, but now I can say it with confidence."

O'Malley even has dreamed up a script to produce the desired result. In his fantasy, the Capitals will score their first-ever triumph over the Montreal Canadiens on the final day of the regular season and squeeze into the playoffs.

A year ago, anyone foreseeing a playoff berth for the Capitals was deserving of instant incarceration, on the grounds he was attempting to perpetrate a fraud. It was on Jan. 23, 1976, that the Capitals defeated the New York Rangers to terminate an incredible 25-game winless streak.

One year later, the Capitals have displayed improvement beyond anyone's dreams. They are fourth in the Norris Division, three points ahead of Detroit, and are capable of beating anyone in the NHL, perhaps Montreal on the final day of the season.

That old "any given day" enters here. The Capitals can beat anyone at any time, but they cannot do so consistently.

Tom McVie has gotten everything possible out of his players, in many cases more than anyone could imagine had been untapped. But there is a limit to what hard work can accomplish. In recent games, the defense has shown signs of slippage with Rick Green injured and Gordie Lane playing tentatively.

Guy Charron, the man they call the Franchise, has scored 24 goals, but only three in the last 18 games. The constant attention of rival checkers, plus his extraordinary duty as penalty killer and power-play point man, have demanded their price. Perhaps, it is time to relieve Charron of his duties on the point and conserve his dwindling energy for the regular shift.

Regardless of personnel problems, the Capitals' most difficult task is the schedule. Only three teams in each division will be in the playoffs, and Montreal is a certainly. Washington has 31 games remaining, 16 at home. Second-place Pittsburgh, 13 points in front, has 33 left, 15 at home. Third-place Los Angeles, nine ahead, has 31 to play, 17 at home. Both teams have three to play with the Capitals and in each case one will be in Washington.

Beating Detroit would be an enormous accomplishment and the situation there is much brighter. Although the Red Wings have 33 games left, only 16 are in friendly Olympia and three games with the Capitals, two are at Capital Centre.

Those playoff tickets in the back of the season parking book will likely go unused, but the Capitals could conceivable beat out as many as five teams, three of them in that awful Smythe Division. Such a result would bring immense satisfaction - and less clout in the amateur draft.

The amazing part of the Capitals' transformation has been their ability to accomplish it without parting with draft choices. The Capitals retain all their selections in the scheduled June amateur draft, one that promises, barring court intervention, to make some superior talent available in the first round. The higher the Capitals' finish, the more difficult Max McNab's task in sifting future diamonds from the junior chaff.

It is difficult to envision the circumstances when the next NHL season winds down in 1978, because divisional realignment is under discussion and the loss of a couple of economically suffering teams is not unlikely. But the evidence already displayed of McNab's shrewd appraisal of talent and McVie's superior leadership makes a playoff berth at that time a most bright possibility.

For the rest of this campaign, it is best to follow the example of veteran center Gerry Meehan, and enjoy each victory as it unfolds.

"That gives us a little bit of a cushion over Detroit." Meehan said following Sunday's 6-3 decision over St. Louis. Asked if he shouldn't be looking up instead of down. Meehan replied. "It's no good to talk about chasing people when you don't play them for a month. We would put undue pressure on ourselves. Our best bet is to work our behinds off every game and play every game to win, one at a time."

The next opponent, Thursday at Capital Centre, is Detroit. A Washington vitory would boost the fourth-place bulge to five points. Considering that the Capitals finished 30 points behind Detroit last season, that's something of a miracle. It's also, realistically speaking about as far as the Capitals can hope to go. But don't stop dreaming, Peter. If Christopher Columbus had been a realist, everybody would still be playing lacrosse.