THE geopolitical center of the United States is shifting further to the south and west. This pleases states like Texas and California, while it upsets New York and Illinois.
It may also bode well for Republicans, though the political implications of all the changes, at this point, are far from certain.
These are among the conclusions and reactions to the last of the preliminary population figures to tumble this week from the computers of the US Census Bureau.
While the numbers for 1990 are still subject to review by states and localities - and many of them have a few unpleasant things to say to federal head-counters - several trends are clear:
The Sunbelt continues to be the great boom area of the United States. Indeed, four states - California, Arizona, Texas, and Florida - accounted for 63 percent of the country's population growth last decade.
Combined, they are expected to gain an additional 15 seats in Congress as a result while five Northern industrial states - New York, Illinois, Michigan, Pennsylvania, and Ohio - will likely lose 11 seats. The Sunbelt powerhouses will also be in line for millions of dollars in additional federal aid, since many programs are based on population.
Residents continue to flee many of the nation's cities, though the exodus is far less pronounced than it was in the 1970s. At the same time, America's ``exurbs'' - areas beyond the suburbs but still within driving distance of cities - are some of the fast-growing areas. This will mean less clout for some cities in national and state affairs.
``One of the great national stories of the 1980s is the continuing development of exurban areas,'' says Alan Heslop, a population expert at Claremont McKenna College near here.
California has reinforced its position as a mega-state. The 24 percent it has grown over the past decade has left it with nearly 30 million people, more than Canada and enough to likely give it seven new seats in Congress. This would bring its delegation in Washington to 52, the most any one state has ever had.
Behind the boom here is sun, what until recently has been a robust economy, and a continuing influx of immigrants.
The growth, though, has come at a cost: more smog, traffic, overcrowded schools, and a lack of affordable housing.
While many of these population trends mirror changes that occurred in the 1970s, there are differences. Not all the Sunbelt states, for instance, are growing like bamboo. Several in the mid-South - Louisiana, Oklahoma, Mississippi - either lost population or grew only modestly.
Nor are all areas of the Northeast and Midwest moribund. Massachusetts grew 3.3 percent over the decade, slightly more than was projected, though it still may lose a congressional seat.
In all, some 19 House seats are expected to change hands after redistricting as a result of the shifts.
Election Data Services, a political consulting firm, projects the big winners, in addition to California, to be: Florida (4 seats), Texas (3 seats), Arizona, Georgia, North Carolina, Virginia, and Washington (one seat each).
On its loser list: New York (3), Pennsylvania (2), Ohio (2), Michigan (2), Illinois (2), and eight other states one each.
None of the figures are final, though. States and localities have 15 days to review Census Bureau population counts and present evidence of people and areas that were missed - something all of them are doing, given the political and economic consequences of the numbers.
In Denver, city officials estimate they stand to lose $140 million in state and federal funds over the next 10 years as a result of the drop in population reported by the bureau.
In Atlanta, where the population has been projected to be off almost 10 percent, city officials hope to convince the bureau that its numbers are far too low - and, if they can't, may go to court.
In New York City, Mayor David Dinkins calls the census's estimate of a 40,000 population drop ``statistical grand larceny.'' He and other big-city mayors complain of an undercount of immigrants and minorities.
While population experts say some of the numbers will be revised upward, many doubt they will change radically.
Some political analysts see good omens for the GOP in the demographic changes. William Schneider at the American Enterprise Institute argues that the rise of the South and the West, Republican strongholds in recent presidential elections, could help the party nationally while the movement of people from cities to the suburbs, another part of the GOP base, could help them within states.
On the other hand, some of the most dramatic population growth in California, Texas, and Florida has been among Hispanics and other minorities, traditionally fertile ground for Democrats.
Other impacts of the population shifts, though, will have to await the outcome of the 1990 elections, which will help determine which party in each state will have the upper hand in redrawing congressional districts.
``To say the shifts are going to benefit one party over the other is premature,'' says Doug Chapin of Election Data Services.