Why is it unfair, the current Egyptian joke asks, to call President Anwar Sadat's crackdown on critics the mummification of democracy?

Because, goes the answer, only something that has been alive can be mummified.

The point is unfair or at least overdrawn. But then, Egyptians traditionally have told each other jokes to make their often unenviable fate appear more bearable.

What seems obvious is that even without the crackdown that is currently going on against opposition politicians, journalists and others, Sadat is in trouble. In the Third World where the only unquestionably strong institution is the army however, there is an all-important difference between being in trouble and real danger.

It is unclear whether, as has been rumored, there was trouble in the army in April which prompted Sadat to act. But Sadat is an experienced survivor.

Simple prudence signalled trouble ahead. An increasingly freewheeling opposition was criticizing a government policy that was stymied in efforts to improve Egypt's wretched economic conditions and to persuade an intransigent Israel to move ahead on Sadat's peace initiative.

At best, time - perhaps a great deal of time - would be needed to make discrenible progress. The euphoria created by Sadat's November visit to Jerusalem is wearing off under the mundane realtities of soaring food prices and shortages.

Sadat himself speaks of no meaningful solution to Egypt's economic problems before 1980 - and his critics claim he is indulging in demagoguery even then. His advisers wond erout loud if any progress on the peace front can be made as long as Menachem Begin remains in office in Israel.

Even if the threatened crackdown turns out to be sugar-coated - as government apologists keep insisting will be the case - Israel now has its first real club to beat Sadat with.

Officials worry in private that Isael may start insinuating that there is no need to hurry neogitating with Sadat now that he seems to be on the skids.

What shocked many Egyptians was not so much the crackdown itself as the panicky way it was carried out.The vague catchall wording of last week's referendum seeking backing for the move against Sadat's foes so outraged people that officials skip with embarrassment over the statistics claiming a 98.27 per cent "yes" vote.

Why did the government bother, people ask, when an earlier referendum - called after the serious food riots in January, 1977 - equipped Sadat with a full repressive arsenal, which he wisely has chosen to use sparingly?

The opposition wonders out loud why Sadat has sacrified his almost universally admired domestic reform which served as both alibi and safety valve for 'Egypt's many problems.

For understandable reasons both the leftwing and rightwing opposition predict that the repression will be total no matter how benign Sadat's intent. Repression, they say, has a logic of its own.

Sadat, meanwhile, alternates carrot and stick. He is capable of such phrases as, "I will crush anyone who casts doubts, but I will use democratic means."

If nothing else, the past month has shown that all kinds of Egyptians have taken Sadat's liberalization policy seriously. Since its first timid beginning four years ago, university professor got up on television and argued face to face with him.

The bar association minced no words in castigating the referendum as "illegal, unconstitutional and a setback for democracy."

Aside from a general feeling of unease about the whole Sadat campaign, Egyptians offer various theories to explain their mood.

Always impetuous, Sadat may have felt the opposition, which he created by decree in 1976, was getting too close to home in its exploitation of various scandals involving his close friends.

Especially harmful were accusations against millionaire contractor Osman Ahmed Osman, a close confidant whose son is married to a Sadat daughter. Sadat angrily said at one point he knew the anti-Osman campaign was really directed against him.

Both the strength and weakness of the present government, political analysts believe, is Sadat's use of former policeman Mandouh Salem as prime minister. The two have kept the army out of politics so far, but the weakness of the system is that Salem passes all of Egypt's manifold problems up to Sadat instead of acting as a lightning rod to deflect criticism from the president.

In recent days Sadat has sought to regain the initiative with the public. He cancelled a controversial speculative real estate deal - involving osman - near the Pyramids, and he rejected a proposed tax bill on grounds that real estate speculators and others with wealth must pay their share of taxes.

As mishandled as things appear to be, analysts still put Sadat's stock as no lower than just before he launched the peace initiative. He is still thought better off than during the Janary, 1977 food riots and infinitely stronger than before he launched the October, 1973 war when he had become the butt for Arab world jokes.