There are only 535 members of Congress -- senators and representatives both. In no other office of the same size does such a high percentage of the employes so regularly disgrace themselves and dishonor the organization they work for.

A search of the records going back six years shows that in that time allegations of serious crime were made against 51 members of Congress. Thirty-one Democrats were accused of theft, receipt of illegal campaign contributions from foreign powers, bribery, kickbacks, etc. Twenty Republicans were accused of the same crimes. Since there is about that ratio of Democrats to Republicans in Congress, the statesmen of both parties seem to have the same greasy palm index.

In compiling this list, names like Pennsylvania's former Republican Sen. Hugh Scott were left off. Shortly before he retired, gravely compromising accusations were made concerning certain moneys he is alleged to have received. A Senate ethics committee, as it invariably does, declined to examine evidence.

Nor does this congressional crime count include somebody like Wayne Hays, the Ohio representative who resigned after he was accused of putting a blond on his congressional office payroll, or Wilbur Mills, the alcoholic Arkansas Democrat, who ran off after a bubble dancer.

Also excluded from the count is J. Herbert Burke, the Florida Republican who pleaded guilty to creating a scene in a nudie bar. Likewise treated as nonserious, and therefore not counted, is the admission in February, 1976, by 18 members of Congress, including the chairman of both the House and the Senate ethics committees, tra-la, that they had been taking gratuities from defense manufacturers in the form of free hunting trips.

On the basis of a few off-the-record discussions with honest lobbyists who have to make it their business to understand and outwit the prevailing patterns of dishonesty, it appears that a sting operation such as the one mountedd by the FBI will only net the greediest and the stupidest office-holders. This investigation, which has focused an accusatory spotlight on seven Democrats and one Republican in Congress, wasn't designed to catch crooked politicians, but gangsters. The FBI agents were like fishermen who cast their nets to get tuna and inadvertently capture porpoises, or is it barracuda?

In any event, the wise people in Washington say the big money drops don't happen as they did in the sting operation, during which, it is being reported, one member of Congress and his associate were videotaped literally wrestling over who was going to get to carry the attache cases full of dough. The smoother operators don't take it in cash and don't take it in Washington. The drop is made in another part of the country and not to the congressperson or any member of his staff, but to someone with no formal connection, perhaps no known connection with the elected official.

Every time a scandal like this hits, acquaintances of the accused shake their heads and say, "I don't understand how so-and-so could be so dumb. Why take a chance like that?"

Crooked politicians probably aren't taking much of a chance. Of the 24 pols seriously implicated in the Korean bribery scandal, only one ever went to jail. He made the mistake of pleading guilty and has publicly kicked himself since then, saying that if he had fought the charges he probably would never have had to pull a day of time. With the help of friends in strategic places, by delay and procrastination, or by making some staff member take the fall in his place, even the dumbest and hungriest can lumber off with fat pieces of meat draped over their teeth.

What percentage of Congress is on the take? These figures would lead one to guess about 20 percent; one out of every five could be selling his or her vote, or stealing in any number of ways.

Nor is the dishonesty quotient among members of Congress likely to drop. There is no ongoing program policing them. Exposure, as in the sting sensation, is invariably accidental. Because of the constitutional separation of powers, it is legally much harder to whomp on a congressional crook than an ordinary soldier in life's various mafias. Congress is supposed to police itself, but pride for one's office seldom supersedes the profits of one's pals. Some day the ethics committee may find itself with a quorum, but don't count on it.