PRIME MINISTER BHUTTO is hanging on, but just barely, in Pakistan. His party won the elections held March 7, virtually everyone agrees. But he cheated to get more seats than he'd earned and as a result his opposition, seeing a second chance to do him in, launched a protest that is now in its seventh week and still growing. Mr. Bhutto, countered, first by offering to hold new elections and then, when the opposition said it would be satisfied only by his resignation, by imposing limited martial law. Several hundred people have been killed and perhaps several hundred million dollars worth of economic damage done. The question of the hour is whether the army will push Mr. Bhutto out of power, or let the aroused crowds push him, ending Pakistan's latest experiment in civilian rule.

The protests in Pakistan have been widely interpreted as the flowering of a genuinely popular democratic movement - inspired partially by India's recent example of voting Indira Gandhi out of office - against a leader who has become arrogant in his exercise of power. Perhaps so. We would be more persuaded that his was the case, however, if the complaints against Mr. Bhutto had been voiced more clearly before he got into trouble. In fact, he was widely credited with being an effective and progressive leader. The scope of the protests against him suggests that he had built up in the Pakistani people a great deal of latent hostility.But if his own mistakes are at the source of his and his nation's present distress, then surely his opponents - by their rejection of the new elections concession he offered as a way out of the crisis - have something to answer for themselves.

There is, however, a more sobering explanation, one arising from Pakistan's widely shared status as a poor country, that is, as a country containing great economic and social disparities. In such a country, no matter how relatively well governed it is thought to be, the tinder of popular discontent is always there, waiting to be touched off by political accident or economic circumstance. There are simply too few people with a stake in things as they are. There are too many people with not very much, or nothing, to lose. Such societies are like unloaded canoes: They can easily be tipped. It's Pakistan's turn right now. Who will it be next month, next year? India? Indonesia? Nigeria? Regrettably, Pakistan's misfortune is not its alone.