When I was a kid, my father for a time drove a 1974 Chrysler LeBaron Imperial, a massive yacht of an automobile whose interior was literally larger, in terms of floor area, than the kitchen of my first apartment in Manhattan.

It was of course a completely irresponsible car to own and drive. But we didn't know that then, even after the first Opec crisis of 1973-74, when gasoline prices went up to the then-scandalous figure of around 40 cents per gallon. In about two years' time, however, car manufacturers and Americans caught on. Detroit made more fuel-efficient cars (the LeBaron of ten years later could practically have fit inside the '74 model). The US lowered the highway speed limit. Dad downsized to a Ford Granada.

But something else happened around that time - these funny-looking things called Hondas started showing up on American roads. Previously, Honda was known in America only as a motorcycle manufacturer, and Japan generally as the source of the shoddier merchandise purveyed by Woolworth's and the like (the phrase "made in Japan" was a punch line on US sitcoms in the 1960s). The idea that Honda could make better cars than Chrysler seemed completely preposterous.

Today, we have a running debate in America about what's happened to once-mighty Detroit. Conservatives blame the unions. Liberals often point to globalization and other macroeconomic pressures. But all a person really has to do is sit for 10 seconds in a Honda Accord and then sit for 10 seconds in a Chevrolet Impala. That person will learn more about the reasons for Detroit's decline in those 20 seconds than in any amount of study.

What afflicts Detroit also afflicts American politics, and therefore America generally. We've had a terrible failure of leadership. In fact, now that I think about it, Detroit has behaved vis a vis Japan almost exactly as the Democratic Party has behaved vis a vis the Republican Party.

Japan overtook Detroit in the 1980s, right around the same time the Republicans seized political control from the Democrats. Japanese car makers offered consumers a more appealing product on the thing that really counted - they built better mid-size family sedans. The Republicans proved more appealing to a majority of voters where it really counted - they promised lower taxes, stricter morality and a tougher stand against the Russians.

And Detroit and the Democrats both responded chiefly by trying to change the subject. Detroit, rather than trying to update its way of thinking and compete with Japan on mid-size sedans, admitted defeat and started concentrating on pick-up trucks and SUVs. The Democratic Party - rather than, say, trying to update its way of thinking and articulate a foreign-policy philosophy that would allow it to compete with Republicans - decided to cede foreign policy to the GOP and emphasize cautious domestic proposals.

Detroit had plenty of time to lead the way on the next generation of hybrid cars, but the American Big Three automakers didn't have the leadership and vision to do it. Democrats had a chance, right after September 11, to put forward a vision of how America should respond to the attacks and comport itself in the world, but the party lacked the leadership and vision to do it.

My analogy breaks down, of course, here: Japan has shown no signs of imperial overreach, corruption and incompetence, while the Republicans have. So while the Democrats seem, potentially, poised to get back on top, for Detroit, it's over. Japan will do them no such favours.

There was a difference between my dad's LeBaron and the next generation of cars because Detroit actually responded to changing markets and social conditions. That stands in stark contrast to Detroit's current failure to respond to new conditions by producing hybrids and fuel-cell cars. Chrysler, taken over this week by a private equity firm, is going to be chopped up and downsized and probably won't exist in two years. That's management's fault - but as usual, the workers and unions will be the ones who'll be screwed.