Democratic standard bearer Michael S. Dukakis, while trailing Republican nominee George Bush by only a narrow margin in national opinion polls, faces a much larger and more dangerous deficit in state-by-state surveys of electoral votes, which will actually determine who wins the White House in November.

Most analysts interviewed by the Los Angeles Times now credit Bush with leading in states with more than 200 electoral votes out of 270 needed for a majority, including two of the biggest - Texas with 29 electoral votes and Florida with 21. By contrast, Dukakis is considered to be ahead in states with fewer than half of Bush's total of electoral votes.These figures could change dramatically as a result of developments in the campaign between now and the Nov. 8 election. But the present calculus, which seems to put Florida and Texas out of the Democratic nominee's reach, imposes tremendous pressure on underdog Dukakis to do very well seven other big states.

In addition to California, the nation's largest with 47 electoral votes, these big states are Illinois with 24, Michigan with 20, New Jersey with 16, New York with 35, Ohio with 23 and Pennsylvania with 25. By the reckoning of Republican strategists and some Democrats too, Dukakis probably needs to carry California and five of the remaining six big states to avoid the fifth Democratic defeat in the past six presidential elections.

This sounds like a staggering task for the Massachusetts governor, considering that recent polls in those states give him a clear advantage only in New York.

"Dukakis has a damn small margin for error," contended Richard Williamson, a former campaign strategist for President Reagan who is an unofficial adviser to the Bush campaign.

"That strikes me as a premature conclusion," replied Tom Kiley, Dukakis pollster and a senior adviser to

he candidate. "We would argue that we have five more weeks to go in the campaign."

Indeed, far from giving up on all the states now consigned to Bush by most polls, the Duakakis campaign now plans what sources call a "major" advertising counterattack in one of the most important of them - Texas, home state both to GOP nominee Bush and to Dukakis's running mate, Sen. Lloyd Bentsen.

Though recent polls show Bush leading in the state by 5 to 10 percentage points, Democrats believe they can win support for the Dukakis-Bentsen ticket with television commercials exploiting Bentsen's televised debate on Wednesday with the Republican vice presidential nominee, Indiana Sen. Dan Quayle.

Regardless of which way Texas ultimately goes, hardly anyone is ready yet to dismiss Dukakis' chances of staging a comeback in other key states around the country.

"I think we're slightly ahead in most of the big states right now, or certainly enough of the big states to get over 270," said Bush campaign manager Lee Atwater. "But no one in our campaign feels the election is in the bag."

The campaign trend has clearly been running in favor of Bush and the Republicans in recent weeks. In mid-August, just before the Republican convention, a survey of state polls by the Field Institute, headed by California pollster Mervin Field, showed Dukakis leading in 25 states with 356 electoral votes, while Bush was ahead in only 15 states with 118 electoral votes.

A similar survey by the institute released Friday shows how far Dukakis has plunged and how high Bush has climbed in the past eight weeks.

Field's compilation of state polls, most of them taken in September, shows Bush ahead in 27 states with 254 electoral votes, only 16 short of a majority. Dukakis is ahead in only eight states and the District of Columbia with a combined total of 92 electoral votes.

Fourteen other states, including three of the biggest ones - California, Pennsylvania and Illinos - with a total of 192 electoral votes, are rated as tossups. The survey puts a state in that category if neither candidate has a lead of 5 points or more.

Particularly ominious for Dukakis is the apparent re-emergence of the Republican grip on the electoral college, which characterized recent presidential elections and which Democrats had vowed to break in 1988.

The Republicans appear to be well ahead throughout the South and the Rocky Mountain West, in states that have provided the GOP with a strong foundation of support beginning with the 1968 election. Meanwhile the Dukakis campaign, like a retreating army, seems to be falling back on small enclaves of electoral votes, mostly in the Northeast, to which the Democratic Party has been confined for most of the past 20 years.