The biennial rediscovery of the middle class is on. Every two years the ladies and gentlemen of the Congress are made to sit straight in their chairs by the force of an insightful lightning bolt that tells them they must go forth and do something for "the middle class."

It isn't easy to do one's self political injury by standing tall for the old M.C. To say it's high time we helped the middle class is akin to saying it's high time somebody did something for America inasmuch as everybody in America defines him or herself as essentially middle class.

There is no such thing as an upper class. Even Nelson Rockefeller'll tell you he's just a regular, middle-class, middle-of the-road, moderate good buddy hangin' on to his CB and hollerin' 10-4 like the rest of us.

As for the lower class, it's gone too. Even the winos have been conscripted into a middle-class auxiliary group known as "the disadvantaged." The disadvantaged are the great-grandchildren of the oppressed who were a lower-class group but they've long since varished into the American past with the red man and the milkman and the Nash Kelvinator, whatever that was.

To help the middle class maintain its beleaguered self, Congress proposes giving a tax credit to families paying college tuition for their children. The administration, cognizant of the fact that such a credit will help the rich members of the middle class far more than the middle-income members, has countered with the suggestion the amount of money allocated for student loans and grants be raised by some billions of dollars.

No one, at least no one with sufficient clout to get his name in the papers, has pointed out that another way of accomplishing the end of making college cheaper for middle-class children is to lower the tuition. Tuition costs could be lowered if professors had to work a normal 7 1/2-hour day. Universities rival the Pentagon, HEW and the now-defunct Penn Central railroad in low productivity per worker.

If the Carter administration would prefer putting out a few billion more dollars to challenging the waste and corruption in higher education, it may be because there are only so many losing battles working politicians want to lose at one time. The administration is already getting badly skunked on the hospital-cost fight.

In the months since the idea was first proposed, the medical industry has been quite successful in persuading members of Congress that government is wrong to seek control of hospital prices. By delay, by maneuver, by lobbyist and loud lament, hospital administrators are convincing enough people that being made to hold their yearly price increases in patient care to a measly 9 percent - down from the 15 percent they're used to - would constitute oppression and a threat to the public health.

Any effort to hit the university with price control or, better yet, reasonable measures of productivity, would only unite the doctors and the professors, an invincible combination. Only an aroused public, if such a mythological beast were to exist outside of song and cliche, would be able to defeat it.

The tuition tax credit proposal is calculated to tranquilize and soothe; it will arouse no one because it appears to be giving the middle class something and therefore it is championed by men like Sen. William Roth, the Delaware Republican who aspires to the currently vacant office of Watchdog of the Treasury.

To get people to do more, to get people to show palpable support for such measures as hospital price controls, the connection between the government spending the money and collecting it from us must be closer. That's what a balanced budget does. It means that every time the hospitals come in for their yearly 15 percent increase, Walter Cronkite will tell us how much our taxes are going to go up.

Maybe that will turn the lethargic mob into the aroused public of our dreams, and if we can't beat the professors and the doctors, we may fight 'em to a standoff.