LESS than a year and a half ago, George Bush was arguably the most popular president of the last 50 years. Today he holds another record: The longest sustained fall in popularity since political polls began in the late 1930s.
The crisis for Mr. Bush boils down to two simple facts: In the history of polling, no president this unpopular has gone on to win reelection. And none has won after trailing his opponent as badly as Bush trails Bill Clinton.
Bush is in such deep trouble for one main reason: the economy. Even with the recession technically over, recovery has been so weak as to elude most Americans. Battered by two years of slow-growing income and a stagnant job market, only 1 in 10 believe the worst is over.
Among the few Americans who believe the economy is improving, Bush leads by a 4-to-1 margin. Among the many who think the economy still is getting worse, Mr. Clinton leads by 4-to-1.
Yet all is not lost for Bush. He has a reservoir of past good will; 90 percent of Americans, after all, did approve of his job performance after the Gulf war just last year. The question is not whether he can achieve broad public support, but whether he can recapture it.
Another point of strength for Bush is that most Americans prefer his party's fundamental view of government - the less the better - to the habitual Democratic preference for active government. This is one of the factors that whittled away the Democrats' claim to majority-party status in the 1980s.
Finally, the president can point to another precedent: In this century, every incumbent who won renomination as strongly as Bush has won it went on to win the general election. That means 1992 is guaranteed to break tradition. Bush either will be the first president in this century to win renomination so strongly and then lose the election; or he'll be the first since political polling began to win reelection after trailing so badly in the summer.
These competing currents, plus the tendency of presidential races to tighten in September, imply a close election. We're not likely to see either a Clinton blowout like the polls show now or the Bush coronation that seemed likely just last year.
Bush might draw hope from Gerald Ford's near-win in 1976, and Harry Truman's famous 1948 comeback. While Mr. Ford was beaten by Jimmy Carter, he did rebound from a 33-point deficit in the summer to an election-day loss by just two points. That may help take some of the sting from Bush's 29-point deficit to Clinton after the Democratic convention.
THERE are more parallels to Harry Truman. He reached 87 percent approval in a June 1945 Gallup poll, shortly after VE Day. But pent-up economic frustrations exploded after the war; with millions of workers on strike, Truman's rating dove to 32 percent approval by September 1946 - down 55 points in 15 months.
Bush hit 90 percent approval in a March 1991 ABC News/Washington Post poll, boosted by success in the Gulf war. But recession-inspired economic frustrations, which had been hammering him the previous fall, soon returned with a vengeance. By June, he was at 35 percent approval - down 55 points in 15 months, precisely matching Truman's dive. Now Bush has slipped further, to 33 percent approval in an ABC/Post survey.
One difference, of course, is that Truman's fall came two years before he stood for reelection, while Bush's occurred in an election year. But Truman also had election-year troubles: After recovering to majority approval in 1947, he fell again to 39 percent in June 1948 - and still managed to win.
One way Truman prevailed was by sharply attacking the "do nothing 80th Congress," which the Republicans had taken over in 1946. Bush also is struggling with a Congress controlled by the opposition party - and blaming it for much of the nation's ills.
But there are significant differences between 1948 and now. Truman faced an overconfident and lackluster opponent in Thomas Dewey. Truman cast himself as a man of the people, whereas polls show that Clinton has the advantage in this measure. Most important, there was no recession in the year leading up to the 1948 election.
The public's economic discontent dovetailed with the departure of Ross Perot last month to give Clinton his record "bounce" in polls after the Democratic National Convention in New York.
This week's Republican convention is one of Bush's best chances to bounce back - although given his current low popularity it will be tough for him to catch Clinton on bounce alone. Above all, Bush must retrieve former Perot supporters, who have turned to Clinton by better than 3-to-1.
Bush's biggest problem is that the economy probably cannot improve fast enough to help him. He may play to his stronger suits - trust, experience, military leadership, and prowess in foreign affairs - and, like Truman, hit the Congress hard and often.
But issues other than the economy are likely to pale in comparison. For all the talk about replacing Dan Quayle, polls consistently have indicated that vice presidential candidates have little effect on vote choices.
Abortion is another issue that's had far less clout than advertised in voting decisions; in the 1990 elections, for instance, exit polls showed clearly that the abortion vote did not determine the outcome of any major races.
That's not to say abortion, Quayle, or anything else is insignificant in this election. In a close contest every vote counts. But it's clear that most votes will depend on the economy - not only its condition, but voters' perceptions of its condition. And that, far more than any other factor, is what's threatening to make George Bush a one-term president.