MIAMI -- Once again yesterday, Paul E. Tsongas' voting strength was limited to upper-income, highly educated whites, and he was unable to crack into Bill Clinton's basis of support among other Democrats, surveys of voters leaving the polling places showed.
That breakdown was especially bad news for Mr. Tsongas, since the surveys showed the Democratic electorate in Florida to be much more heavily white and much more highly educated than it is likely to be in most primaries down the road.
Mr. Tsongas, a former Massachusetts senator, and Mr. Clinton, the Arkansas governor, more or less split the white vote in Florida, but Mr. Clinton won 75 percent of the black vote.
Mr. Tsongas led Mr. Clinton in Florida among the one in four Democrats with incomes above $50,000, but Mr. Clinton was far ahead among the rest.
Mr. Tsongas also did well among the nearly two-fifths of Florida Democratic voters with college degrees, but Mr. Clinton carried about three of five of the less-educated Democrats.
The situation was even more pronounced in Texas. There, fourth-fifths of blacks voted for Mr. Clinton.
The third Democratic candidate, former Gov. Edmund G. Brown Jr. of California, won less than 15 percent of the vote in Florida and less than 10 percent in Texas, and seemed from the exit polls to have drawn voters away from Mr. Clinton and Mr. Tsongas fairly equally.
In the GOP races in Florida and Texas, the polls also reinforced the conclusions drawn from earlier primaries. President Bush did much better among women than among men, and Patrick J. Buchanan ran strongest among Republicans who say the economy is in poor condition.
Illustrating the tensions from the combative primary campaigns in both parties, up to one-quarter of the Democratic voters in Florida said they would vote for Mr. Bush in November if the candidate they supported in the primary today did not win the nomination.
By the same token, about 40 percent of Buchanan supporters in Florida said they intended to vote Democratic in November if Mr. Bush was the Republican nominee.
In the Florida campaign, Mr. Clinton tried to appeal to the elderly by portraying Mr. Tsongas as an advocate of cutting Social Security benefits, but that seems to have had little effect on the outcome. Mr. Clinton was 10 to 15 percentage points ahead in every age bracket.