Listen to a discussion of the American future and you're likely to hear stated as fact two highly debatable observations.

One - I last heard it in a presentation by an Urban Institute spokesman - is the offhand reference to the American 'decision' to become a 'multicultural society.'

The other stresses demographic inevitability. A prominent law professor expressed it in a weekend debate about diversity - clinching, she imagined, her point about the need for more affirmative action by telling her student audience that whites will be just another minority group by the year 2040.

Those who say such things fear no contradiction. The speaker who touts the 'decision' about multiculturalism proceeds as if the American people debated and chose to become a multicultural society, rather than having that choice forced on them by Washington-based miscalculation in which they had no hand.

And the demographic transformation forecast, inevitably put forth in tones combining scientific certainty and liberal triumphalism, may come true and may not. That depends almost entirely on the political choices made by the U.S. government and the American people in the years to come.

When the United States eliminated the 'national origins' provisions in the 1965 immigration reform, no lawmakers foresaw a large influx of immigrants from Asia and Latin America, indeed supporters of the reform explicitly denied such a possibility. No one 'chose' multiculturalism.

The demographic forecasts are highly changeable. If, for example, it is desirable to reduce whites to minority status by the year 2040, why should our society delay even that long? Surely we could get 50 million people from Mexico and Central America and China here by the end of this decade (and save money on the federal Border Patrol and Immigration and Naturalization Service budgets to boot).

There is, as well, an African immigration stream which was started up by the most recent (1990) revision of the federal immigration statutes. It is still in the embryonic stage, yielding most visibly an increase in street peddlers (and the most recent Central Park rapist). But it could be juiced up with no effort at all It would be no more difficult to persuade 30 million sub-Saharan Africans to migrate here than it would be to convince Haitians.

In short, if the best society is a multicultural one of primarily Afro-Chicano ethnicity, there's no need to wait until 2040. Why deny ourselves and our children the great benefits of Third Worldism that we are planning for our grandchildren?

I'm being facetious, of course, in order to make a larger point. The huge demographic transformations which the U.S. is undergoing are a) an issue about which the American people have never been consulted in a politically meaningful way; and, b) something which the federal government could accelerate or decelerate dramatically, depending on the course it chooses in the years ahead.

'While politicians have failed to

address immigration as a national

issue, the American people are

confounding them by finding ways to

put it on the national agenda.'

While politicians have failed to address immigration as a national issue, the American people are confounding them by finding ways to put it on the national agenda. California's Proposition 187, the much-maligned 'Save Our State' ballot initiative, represents the first effort in this realm - and certainly not the last.

The wave of scorn which has been heaped upon Prop 187 by the national press and the Beltway politi-cians of both parties is the revealing sign of the vast gap in morals and perceptions which has opened up between the country's political elites and its citizenry.

It is, of course, legitimate to argue that denying illegal aliens access to welfare and social benefits will neither increase their prospects for assimilation nor force them to go back home. But Californians have been left with little choice. There is no party in Washington advocating measures to make it impossible for several thousand people to run across the border every night.

While the U.S. apparently has no difficulty keeping the Iraqi army out of Kuwait, dissuading unwarmed Mexicans and Salvadorans from crossing into California is presented to the American people as Mission Impossible.

For California's voters, the issue does not turn simply on the illegal aliens currently resident there. Of course, it is doubtful that they were greatly assured by the sea of Mexican flags leading the Los Angeles demonstrations against Prop 187.

Nor would they be comforted by attacks on Prop 187 in The Nation, an ideological lode star of D.C.'s liberal Democrats. In one recent issue, Leslie Silko enthused that borders were obsolete 'It's no use; borders haven't worked and they won't work, not now, as the indigenous peoples of the Americas reassert their kinship and solidarity with one another.'

But only an un-California-like pessimism would lead anyone to doubt that the four million or so Mexicans now in the Los Angeles area could be assimilated in a generation or so, as English language education and intermarriage do their slow transformative work.

Only the constant and accelerating replenishment of the pool of illegal aliens will ensure that such assimilation will be postponed or abandoned.

The immigration debate, which has been jump-started by Prop 187, has antecedents in the last major effort to restrict immigration the national origins statutes of the 1920s. But the consequences of that last immigration 'pause' were, in fact, quite positive - despite the universally bad press they now receive.

During the 40-year breathing space, the offspring of the millions who came here poor and illiterate in the century's first decades learned English and baseball - and, in many cases, higher mathematics and law.

The 'xenophobic' United States of the 1920s and 30s was virtually alone among the world's industrial nations in weathering the Great Depression without significant internal violence or powerful challenges to democratic governance. While Hitler and Stalin reigned supreme and their emulators sprouted up throughout Europe, Americans were led by Franklin Delano Roosevelt.

Does anyone imagine that today's multicultural United States could display that much social cohesion under the stresses of depression and global war? And how would the even more 'diverse' U.S. that is being planned for the next century fare under such crises?