Almost 30 years have passed since Hawaii joined the union as our 50th state. Now a small breeze from Capitol Hill whispers of possible expansion. A deal is being talked by which statehood would be granted more or less simultaneously to Puerto Rico and to the District of Columbia.

My guess is that nothing much will come of the talk. The zephyr will die down, Puerto Rico will remain a commonwealth, and the city of Washington will muddle along under its present incompetent government.The District of Columbia votes overwhelmingly Democratic; if it should become a state, two more Democratic senators and one more Democratic representative would be a certainty. Republicans would use every parliamentary weapon in their arsenal to prevent this.

Puerto Rico, by contrast, has Republican leanings. If Puerto Rico were brought into the union, there would be at least the possibility of offsetting Republican senators and perhaps a net GOP gain in the House. In his recent budget message to Congress, President Bush said that he personally favors statehood; he asked for legislation that would let Puerto Rican voters express themselves on their options.

Puerto Rican statehood is at best a distant bridge; we may talk about crossing it when we get to it. The relevant considerations are quite different in the two instances. Puerto Rico presents no particular constitutional problems; it has a large population, diversified industries and prosperous agriculture.

Its people cannot vote in presidential elections, but they pay no federal income tax either. As a commonwealth, Puerto Rico is treated in federal programs as if it were a state. The people have a pretty good thing going. In 1967 they voted in landslide proportions to maintain the status quo.

Walter Fauntroy, the District of Columbia's non-voting delegate in the House, has reintroduced his statehood bill. Like its unsuccessful predecessors, the bill would create a State of New Columbia. The present District of Columbia would dwindle to the "National Capital Service Area," taking in the White House, the Congress and the Supreme Court, along with defense facilities to the south and east of the city.

The idea of transforming the city of Washington into the state of New Columbia has not improved with age. It remains as preposterous as ever. The city has no significant industry; it has no agricultural or natural resources at all.

One argument alone supports the Fauntroy bill: The 600,000 residents of the district pay the same taxes other citizens pay; they are obligated to the same military service; but they have no voting representation in Congress.

Those who live in the district reside here under their own free will; the district, with its non-voting rule, was here long before they were. In any event, the district's pathetic record of participation in local elections suggests that few residents feel sorely oppressed by the deprivation they bear.

The constitutional obstacles to statehood by statute are impressive. The 23rd Amendment, granting three electoral votes to "the district constituting the seat of government of the United States," cannot be repealed by implication.

Presumably a handful of voters would remain legally domiciled in the "National Capital Service Area." One thinks of two offhand: George and Barbara Bush. Others reside in military housing. It is unthinkable that these 50 or 60 residents would be entitled to three presidential electors.

Serious practical problems militate convincingly against turning control of the capital city to a synthetic state. The national government simply cannot permit itself to become hostage to any outside authority. The district is not the property of those who live here. The district belongs to all the people of the United States. This power can no more be abandoned by statute than the power to regulate commerce.

No valid objection can be raised to a Puerto Rican plebiscite. But statehood for the city of Washington? No way, not now, not ever.