EDITORIAL OK: let's put this all in perspective.

Gavin Newsom did something almost unbelievably, incalculably stupid. He's in a lot of political and possibly legal trouble.

He has just admitted to having a drinking problem and is going to seek "treatment" — although it's not clear at all what that means, except that he won't be entering a residential center.

The heart of the scandal was just an affair — yes, an affair with a subordinate, which is a real problem (and something most of corporate America put an end to 20 years ago) — but nobody's dead, he hasn't started a war, the city isn't about to collapse, and the world will keep turning. It seemed silly to us to call on Newsom to resign over that, just as it was silly for the Republicans to impeach Bill Clinton over an Oval Office blow job.

But there's a much bigger problem here.

For months, long before this tawdry story made the front pages, it's been clear that the mayor of San Francisco isn't focused on the job. For whatever reason (and there may be many), Newsom has been checked out for quite some time now. As we reported in "Mayor Chicken" (1/10/07), he never attends public events that haven't been carefully scripted.

He is, we noted in our Jan. 10 cover story, "the imperious press release mayor, smiling for the cameras, quick with his sound bites, and utterly unwilling to engage in any public discussion whose outcome isn't established in advance."

And whether we like it or not, this latest "lapse in judgment" — and Newsom's embarrassing failure to deal with it properly — is only going to make things worse.

To be blunt, for a lot of reasons that have little to do with this tabloid sensation, we don't see how Newsom can effectively run San Francisco for another four years. The mayor's latest mess isn't a scandal as much as a symptom of his shaky grip on the frighteningly tricky world of high-stakes politics. He's acting like a dizzy kid at a rock star party who doesn't have the maturity to handle what's coming at him. Even his close allies have warned us that the wheels are coming off his administration. It's not even clear that he wants to be mayor.

We wish Newsom well in his battle with alcoholism. But for the good of the city (and the causes he claims to care about), he'd be better off announcing he isn't going to run for reelection now.

That wouldn't be the end of his political career — plenty of people (John Burton comes to mind) have taken some time off from politics to deal with their personal lives and come back much stronger. It might be the best thing Newsom could do for himself.

Newsom says right now that he's staying in the race, but he's clearly wounded; that air of political invulnerability has taken a hit. When a local politician is looking bloodied, the sharks typically start to circle. That hasn't happened yet; if anything, over the past few days, the highest-profile potential contenders ...