A year and a half into his presidency, George Bush still enjoys opinion poll ratings that would be the stuff of dreams for almost any other politician. But there is one savvy, charismatic political leader who stands just about equal with Bush in the esteem of American voters: Mikhail Gorbachev.

A new Washington Post-ABC News poll and interviews with people from coast to coast show that Americans have enormous respect and a kind of affection for the Soviet president. Those warm feelings for Gorbachev, in turn, have helped to spawn a rapid reversal of Americans' long-held view of the Soviet Union as a military threat.

"Gorbachev . . . has taken a lot of risks, and I really respect him for what he's done," said Mindy Kaplan, 23, a saleswoman in Palatine, Ill., just northwest of Chicago. "He's helped to make nuclear weapons less of a threat, and he's helped to make Russia not be the big bad wolf."

Jeffrey Chong, 28, a commercial photographer in Westchester, N.Y., chimed in: "I'm all for him. I say, Gorbachev, go for it!"

The survey responses and interviews show that Gorbachev's high standing among Americans reflects a widely positive response to the revolutionary changes that have taken place in what used to be called the Soviet Bloc. Americans polled last week made clear by a wide margin they feel that the two superpowers have genuinely achieved accommodation in place of confrontation.

Ironically, the minority of Americans polled last week who dislike the Soviet leader -- one out of four -- would find themselves in a majority in the Soviet Union, where Gorbachev's popularity has plummeted as his country's economic problems have deepened.

Experts in academia will be debating for years about the causes of the transformations sweeping the Soviet Union and Eastern Europe. But people interviewed in cities across the United States have already decided that the credit should go to Gorbachev.

"He's the best guy they've ever had," said Carlos Bentley, 27, a carpenter in Austin, Tex. "He got the wall torn down, he's letting those countries in Eastern Europe go, he's having a summit in Washington."

For this week's Washington summit, consequently, Gorbachev is coming to a country ready to welcome him warmly. In the Post-ABC poll of 1,526 adults surveyed a week ago, 73 percent said they have a "favorable impression" of the Soviet president, with 25 percent responding "unfavorable."

That percentage, slightly below Bush's recent scores, means that the Soviet leader has a higher "favorable" rating among Americans than most U.S. presidents achieve.

Americans seem to trust the Soviet leader as well. Asked whether Gorbachev's actions reflect an honest desire for peaceful relations or merely good public relations, those surveyed replied by 2 to 1 that he is honestly working for a more peaceful world.

Borrowing a phrase from George Bush, Deborah Kerr, 35, treasurer of the Conrad N. Hilton Foundation in Los Angeles, said: "Gorbachev is the point of light for the next step in world peace. I have a really good feeling about this opening in relations between the two countries. It is long past due."Fear of Soviet Union Is Diminishing

Victor Aguilar, 33, a baggage handler who frequently discusses political issues with his friends over his daily cafecito in a downtown Miami cafe, held forth on the Soviet leader recently, talking in English to a questioner and translating his own remarks into Spanish for his neighbors.

"Gorbachev is looking out for the future, for the world, I think," Aguilar said. "I don't think {Russia} is much of a threat now."

As Americans come to admire Gorbachev more, they seem to fear his country less.

By 2 to 1, people surveyed in the Post-ABC poll have accepted the notion that the United States and Soviet Union are near an armistice in the 40-year Cold War. Asked whether they think "the Cold War between East and West is coming to an end," 66 percent agreed, and 32 percent disagreed. Eleven months ago, the same question drew 48 percent replying "disagree" and 47 percent saying "agree."

By overwhelming majorities, people told the poll-takers that drug trafficking, terrorism and Japan's economic power are greater threats to U.S. security than is the military might of the Soviet Union.

Just 18 months ago, a majority of Americans still felt that the Soviet military was a greater threat than the Japanese economy. But in the latest survey, only 21 percent saw the Soviet military as the greater concern.

In fact, the demise of the Soviet Union as an object of dread evidently has not made Americans feel better about their country's fate. By 56 to 43 percent, those surveyed said the United States is becoming less influential in world affairs. Almost all of them said this development is a "bad thing."

"We're not really doing anything of importance right now," said Joe Lewis, 21, a University of Texas undergraduate. "We're just in kind of a holding pattern, it seems to me."

The sense that there may be other bears in the woods, even though the Soviets now seem friendly, may explain Americans' indecision about future defense budgets. Asked whether changes in the communist world mean that the United States can cut military spending, respondents split, with 49 percent on each side of the issue.

Still, many of those surveyed have started to think anew about the meaning of terms such as "global influence" and "superpower."

"There's really no need for a superpower anymore if nobody needs or wants a police force," said Ron Kercheville, 44, a haberdasher in Austin.

But then, looking at the same picture from a different angle, Kercheville concluded that the United States still may be a superpower of sorts. "I would say our ideals would indicate that we are indeed a superpower if all of Eastern Europe wants to be like us," he said.

For many Americans, however, superpowers, summits and the like are little more than distractions from the realities of daily life.

While official Washington is building up an enormous head of anticipatory steam in the days before Gorbachev's arrival Wednesday night, much of the rest of the country has remained largely underwhelmed.

Fully 51 percent of those surveyed last week said they had not really followed news reports about the forthcoming summit. Many of those interviewed by Washington Post correspondents said their reaction to the meeting has been to ignore it.

"I'm sure it has a big impact on the lives of the Germans," said an uninterested David Lopez, 18, a high school senior in Austin. "Maybe it'd affect me more if I lived over there, but I'm worried about the U.S.A." Lopez cited the problems of drug abuse and poverty.

Asked her views on the summit, Stephanie Strickle, 19, a New York University student, gave a blank look. "I'm so uninformed," she said. "I had absolutely no idea it was happening." Similarly, many of Strickle's neighbors in Manhattan's East Village said the New York City area's recent racial strife, the bizarre cold weather and the delicious daily reports on Donald Trump's associate, Marla Maples, were hotter news items than a superpower summit.

Among Americans familiar with world events, the personal popularity of Bush and Gorbachev has won them sympathy on questions of independence for the Baltic states of Lithuania, Latvia and Estonia.

Only one-fourth of those surveyed said their view of Gorbachev has become more negative because of his stern stance toward Baltic independence movements. As for Bush, 60 percent of the respondents said his hands-off approach to the issue has been "about right," with 31 percent saying he has been "not tough enough" with the Soviets.

Stunning Shift of Opinion Seen in Results

Respondents demonstrated no great passion for the Lithuanian independence movement. Asked whether the United States should grant recognition to rebellious Baltic states even if it would hurt U.S.-Soviet relations, 48 percent said no and 47 percent yes.

That may reflect a general willingness, evident in Post correspondents' interviews, to give Gorbachev the benefit of the doubt. Largely because of their regard for Gorbachev, many Americans seem to be softening long-nourished animosities toward the erstwhile "evil empire."

"I feel so bad that we ever felt that way," said Totty Luquee, 32, a flight attendant in Miami, as she reflected on President Ronald Reagan's harsh criticism of the Soviet Union. "It wasn't right. They are just like Americans, and we all human."

"The communists are not all that bad," echoed Herbert Smith Jr., 35, discussing global affairs in New York while holding the ladder for a fellow worker at his awning company.

"We considered them as the enemy," Smith added, "because of their way of life. But we're basically all the same. They're very cultural, very artistic, just like we are. What's the guy's name with the ballet?"

When they sit back and ponder, however, Americans recognize that astronomical popularity ratings for a Soviet communist leader and mellowing attitudes toward the Soviet Union represent a stunning shift in U.S. public opinion. But respondents said these remarkable changes were spawned by remarkable events.

When pollsters asked "did you ever expect to see in your lifetime" the recent changes in the Soviet Union and Eastern Europe, 82 percent replied no.

For that matter, Americans never expected to see a Soviet leader such as Gorbachev, a man who evokes words of esteem, awe and outright wonder among people all over this country.

"I admire Gorbachev enormously," said Russell Arnett, 69, a filmmaker sipping coffee in a Ukrainian cafe in New York. "What he's doing, what he's doing is so radical we don't even understand it."

Special correspondents Laurie Goodstein in New York, Lauren Ina in Chicago, Mary Jacoby in Austin, Jill Walker in Los Angeles and Cindy Ycaza in Miami contributed to this report.