The failure of health care reform, in turn, doomed the Clinton presidency to second-rank status. The government was well run (something we’ve learned to appreciate now that we’ve seen what a badly run government looks like), but  as Mr. Obama correctly says  there was no change in the country’s fundamental trajectory.

So what are the lessons for today’s Democrats?

First, those who don’t want to nominate Hillary Clinton because they don’t want to return to the nastiness of the 1990s  a sizable group, at least in the punditocracy  are deluding themselves. Any Democrat who makes it to the White House can expect the same treatment: an unending procession of wild charges and fake scandals, dutifully given credence by major media organizations that somehow can’t bring themselves to declare the accusations unequivocally false (at least not on Page 1).

The point is that while there are valid reasons one might support Mr. Obama over Mrs. Clinton, the desire to avoid unpleasantness isn’t one of them.

Second, the policy proposals candidates run on matter.

I have colleagues who tell me that Mr. Obama’s rejection of health insurance mandates  which are an essential element of any workable plan for universal coverage  doesn’t really matter, because by the time health care reform gets through Congress it will be very different from the president’s initial proposal anyway. But this misses the lesson of the Clinton failure: if the next president doesn’t arrive with a plan that is broadly workable in outline, by the time the thing gets fixed the window of opportunity may well have passed.

My sense is that the fight for the Democratic nomination has gotten terribly off track. The blame is widely shared. Yes, Bill Clinton has been somewhat boorish (though I can’t make sense of the claims that he’s somehow breaking unwritten rules, which seem to have been newly created for the occasion). But many Obama supporters also seem far too ready to demonize their opponents.

What the Democrats should do is get back to talking about issues  a focus on issues has been the great contribution of John Edwards to this campaign  and about who is best prepared to push their agenda forward. Otherwise, even if a Democrat wins the general election, it will be 1992 all over again. And that would be a bad thing.