Manila — Businessmen here like to joke that Makati, Manila's modern high-rise commercial district, has become a ''liberated zone'' - the base area for the middle-class revolt against the Marcos regime.
Yellow streamers - the color taken to symbolize Benigno Aquino, the opposition leader murdered on arrival at Manila airport on Aug. 21 - hang permanently from the Makati stock exchange. A few buildings away, a large yellow banner - ''no reconciliation with dictatorship'' - is draped over the Philippines bank building. The bank is owned by the family of Salvador Laurel, the most prominent though most tepid of the opposition leaders.
But the focal point of the zone is just across the road - the 20-story headquarters of the Bank of the Philippines Islands (BPI).
The bank is part of the financial empire of the Zobel family, which created Makati and the surrounding luxurious walled villages with their armed guards.
Each Wednesday and Friday afternoon a number of rich villagers head for the BPI building to join in the noise barrage against the Marcos government.
On these days from 2 to 5 p.m., Ayala Avenue becomes choked with cars, all blaring their horns. Office workers shower confetti - shredded yellow pages, naturally - from their windows. The police keep out of the way these days after the unfortunate publicity that followed a tear-gas and baton attack on the demonstrators some weeks ago.
Enrique Zobel, chairman of BPI and a friend of both Marcos and Aquino, is said to watch these proceedings from his 19th-floor offices. Some businessmen would like to see him replace Marcos.
On nondemonstration days, newspaper vendors in the capital do a brisk trade in the scruffy tabloids that have popped up since the Aquino murder. All are virulently antiregime; one is funded by the Roman Catholic Church. Some vendors sell more of these than the established dailies, whose circulation has plummeted since the murder.
Vendors also sell Ninoy (Aquino's nickname) T-shirts and sun visors, or ''I Love Aquino'' bumper stickers. The stickers, with a red heart for the word love, now seem to outnumber the ''I Love New York'' stickers that inspired them.
This week a new T-shirt is on the market. The front reads ''Marcos Loves You.'' The back cautions ''joke only.'' A few months ago such blatant ridicule of the President would have been unimaginable. Today it is commonplace.
The regime's credibility seems to have disappeared here. The suspicions about the Aquino murder that surfaced immediately after the killing have become firm convictions. People - and some members of the press - joke openly about the alleged involvement of the Aviation Security Command in the killing. That unit had been assigned to protect Aquino.
And in the street the guilt of President Marcos, or at least that of his closest aides, seems to be taken for granted.
But at the same time the so-called middle-class revolt seems to be cooling, despite a prominent role in many public demonstrations by Corazon Aquino, widow of the slain leader. The protests have become part of the regular social calendar - noise barrages twice a week, then the Run on for Aquino and for Resignation (ROAR) on the weekend.
Every Sunday morning for the last month or so several thousand people in Aquino T-shirts have been jogging, hobbling, or limping a five-mile route along the harbor. At the end of the run they are met by their drivers, attend mass, or have brunch on the grass.
Other protests are equally creative - they were after all devised by advertising men. There is the window-shopping campaign. Middle-class women are encouraged to visit shops owned by presidential cronies, try on clothing and generally tie up business, then leave. At one of the most successful of these, a woman had the shop's public address system page her driver. She gave as the driver's name Rolly Galman - Aquino's alleged killer.
The campaigns are continuing but they are basically nonthreatening to the Marcos regime. The proliferation of jokes makes this observer think of other authoritarian countries, where they are both a form of dissent and an expression of frustration.
Though the regime is discredited, it is far from powerless. The Army shows no sign of disloyalty to the Marcos government. The President can invoke a formidable battery of subversion laws if he wishes, and since the Aquino killing he has made it clear he will use both weapons if necessary.
This has left Marcos opponents in a quandary. ''The only way we're going to get rid of this guy (the President),'' a businessman said, ''is by a head-on confrontation. But no one seems willing to lead it.''
Although officially united in its demand that President Marcos resign, the opposition seems destined to dissolve soon into its old factions.
Mr. Laurel would happily run in almost any election the President calls next year. The leader of a more radical group, Justice for Aquino Justice for All, Jose W. Diokno, refuses to have anything to do with the regime.
Given the lack of opposition unity, it is not surprising that the people who march in the rallies are confused.
A women's rally that brought some 8,000 women onto the street Oct. 28 showed a remarkable diversity of attitudes. ''The Grenada invasion was good,'' said one demonstrator; ''why don't the Americans do the same here?''
The overwhelming majority of last Friday's demonstrators would probably have disagreed. Many Marcos opponents fear - and suspect - an American political intervention.
But if the opposition seems to be losing momentum, the regime is sinking deeper into crisis. The country is at times leaderless - even presidential intimates admit that Marcos alternates between considerable energy and profound fatigue.
Marcos announced this week that the prime minister would take over his duties should he become incapacitated. But it remains to be seen whether Prime Minister Cesar Virata's designation as successor will relieve widespread concern about the country's political future.
Another difficulty is that the government is almost broke: Foreign currency has been pouring out since the Aquino assassination. In the first half of October alone $711 million left. ''We've lost 20 percent of our foreign deposits ,'' said an official of a large bank, ''and we're doing much better than most.'' The country's balance-of-payments deficit stands at a record $2 billion. And the devaluation of the peso after the Aquino killingled to a rise in food prices and labor unrest.
Given the difficult times that seem to be coming for their country, some Filipinos are reverting to what one of them calls ''our old schizophrenia - we crack jokes, go out and demonstrate, but we don't think too clearly about what's coming next. Because frankly, when I do think about the future, it scares me stiff.''