Reagan backs statehood for Puerto Ricans; do they?

President Reagan's support for proposals to make Spanish-speaking Puerto Rico the 51st state in the American union is likely to intensify the debate on this issue.

Mr. Reagan's statement broke longstanding presidential tradition. The White House from the time of Franklin Roosevelt has held that Puerto Rico's status is a matter for its people to decide and that the United States government will go along with their decision.

No one knows for sure how Puerto Ricans really feel about their island's status - whether they want statehood or the present commonwealth arrangement. Only a small minority appear to support complete independence.

The President's stand is sure to please Puerto Rican Gov. Carlos Romero Barcelo, an ardent supporter of statehood whose New Progressive Party is linked with the stateside Republican Party. It was after a session with Governor Romero Barcelo Jan. 12 that Mr. Reagan announced his support for statehood.

Despite his views on statehood, the governor had not been expected to push for statehood during his second term because of the narrowness of his victory in November 1980 over pro-commonwealth former Gov. Rafael Hernandez Colon.

Now with Ronald Reagan's blessing for his cause, he may well push for a plebiscite on statehood. In the last such plebiscite, Puerto Ricans opted for commonwealth by a substantial margin. That was during the era of the late Gov. Luis Munoz Marin, the architect of commonwealth and of modern Puerto Rico.

But ''Don Luis'' is no longer around, and statehooders have been winning more elections in recent years. There has been little shift, however, in the islanders' substantial rejection of independence.

Despite the noise and clamor of the ''independistas,'' they remain a small minority. They have the capacity to disturb the political calm, and terrorist elements can damage property. But the independence cause has won only some 5 to 10 percent of the vote in elections in the last four decades.

This, of course, could change. Some island commentators suggest it is happening right now, partly as a result of the Reagan administration's budget cuts, which have eaten into many programs that over the years have become very important in Puerto Rico. For example, cuts approved so far would cut federal receipts on the island by $650 million.

Governor Romero Barcelo has fought hard to stem the cutback tide. But he has had only limited success. He again pressed the point in his meeting with President Reagan. There is no indication, however, that he got more than sympathy from the President.

Yet by supporting statehood, Mr. Reagan gave Governor Romero Barcelo indirect support on the issue of federal funds for the island. It is the governor's contention that statehood would open the door to many federal programs now denied Puerto Rico.

Not all island commentators agree with the governor. The issue of federal funds for Puerto Rico is hotly debated. Commonwealth supporters have long held that it is under commonwealth that the island benefits the most, for not only does it receive approximately $4 billion in federal support, but also Puerto Ricans do not pay federal taxes on income earned on the island.

They would be subject to such taxation if the island became a state.

A sizable portion of the federal aid to Puerto Rico goes to the food stamp program. Some 65 percent of Puerto Ricans on the island receive stamps.

The food stamp program, moreover, is a safety valve, helping dampen down frustrations felt by many Puerto Ricans about their status. Underneath the debate over the issue of commonwealth or statehood is the Puerto Ricans' worry about the preservation of their Spanish heritage as a part of the US.

This worry has been around for a long time. It is likely to intensify if it appears statehood is coming. Statehood supporters insist the island would retain Spanish as its language -- and that could present a problem for Congress, which must approve statehood.

The scenario for statehood calls for islanders to approve the move in a plebiscite, then for the island legislature to endorse the move, and finally for the US Congress to adopt a measure making the island the 51st state.

It is not a short process. It could take a decade -- and a lot can happen in that time.