Under Congressional reapportionment next year, Florida could pick up as many as four seats in the House.

The Constitution requires that a census be held every 10 years and that it be the basis for Congressional reapportionment.

Those rulings relied on a Federal Census Act provision that requires the Secretary of Commerce to use sampling in determining population "except for" the purpose of Congressional reapportionment.

The mayor's office commissioned the poll from Johnson because of concern that inadequate counting might compromise activities like Congressional reapportionment, City Council expansion and Federal spending.

Florida is expected to be one of the big winners in Congressional reapportionment next year.

If only residents had been counted for Congressional reapportionment, as was the case with every census except 1970's, Massachusetts would have kept its 11th seat.

But Democratic leaders here said his conversion was part of a much broader battle over Congressional reapportionment for the 1990's.

Later, more detailed figures become the basis for Congressional reapportionment, state legislative redistricting and the distribution of tens of billions of dollars in Federal aid to states and local governments.

Census counts also have a role in political power since they are the basis for Congressional reapportionment and legislative redistricting.

Under an amendment approved by the Senate, the use of Federal funds would have been prohibited for counting illegal aliens for the purpose of Congressional reapportionment.