FOR most Americans, the findings released by the Census Bureau last week can seem simply a matter of curiosity, as we trace the ongoing shifts of populace from the Frost Belt to the Sun Belt, from the interior to the coasts, from cities to exurbia. But for state, city, and county officials, the census numbers set off two frantic weeks of peering at maps and poring through computer printouts. In statehouses and on Capitol Hill, too, the numbers receive careful scrutiny.
The new figures are the last preliminary data to be issued by the Census Bureau before it reports the official results of the 1990 headcount. Much is at stake in the accuracy of the final count. The official numbers will determine the amounts of federal aid that will be allocated to different communities, and the figures also will affect the apportionment of congressional seats among the states and the boundaries of federal and state legislative districts.
Administrators in 39,000 state and local jurisdictions have until Sept. 9 to challenge the bureau's numbers by demonstrating that the enumerators overlooked or undercounted parts of their areas. Predictably, in communities where the Census Bureau figures fall below local calculations - such as New York City, Philadelphia, Houston, and Atlanta - officials are raising an outcry. Among their complaints: that the bureau missed newer housing developments and undercounted transient populations like the homeless and recent immigrants.
Some of these claims may well have merit. They come from self-interested parties, however. The Census Bureau will make adjustments to reflect well supported claims, but some healthy skepticism is warranted.
Dissatisfaction with the final count undoubtedly will revive demands, made after the 1980 census, for a mandatory ``aftercount'' of selected groups and formal adjustments in the results.
Meanwhile, politicians are eyeing the latest numbers with anticipation or foreboding. Nineteen seats in the House of Representatives will be shuffled from losing states - New York (-3), Illinois, Michigan, Ohio, and Pennsylvania (-2 each) - to winning states - California (+7), Florida (+4), Texas (+3). In states losing seats, infighting among incumbents can be expected over which districts will be eliminated.
In many states, even where the congressional representation stays the same, district lines will be redrawn to reflect shifts of population concentrations. Control of the gerrymandering process will be a prime goal in state gubernatorial and legislative races this fall.
Beyond the political changes wrought by the census are the demographic changes it records. Among these, the impact of immigration stands out. Almost 40 percent of the country's population growth during the '80s came from overseas - and much of that settled in California. Helping these newcomers become full participants in the American democracy will be a prime task in the decades ahead.