If sackcloth came in pinstripes, they’d have been wearing sackcloth.

As it is, they came to Capitol Hill well-tailored, well-coiffed, if a little the worse for wear. They had, after all, spent some hours on the road.

Better that, they realized, than another jaunt in their private jets. The jet jaunts didn’t work out so well, public-relations-wise. They were, in fact, a disaster of epic proportions.

So this time, they hit the highway. It might take longer, but it gave them a better chance of reaching their destination:

Your wallet.

But oh, the indignity of it all! The vultures were out, and the photographers, too. “NO JET THIS TIME” — only slightly sneering, those first four words of the caption on that great big Page One photo in The New York Times.

“Rick Wagoner, the chairman of G.M.,” read the rest of it, “rode on the passenger side of a Chevy Wednesday on his way to Washington.”

“EMPEROR CLEANS TOILETS,” it might as well have said. The world as we know it, turned totally upside down.

Well, maybe not totally. They might have dialed the attitude down from Hummer to humble, but the Not-So-Big Three automakers were still asking for money, and plenty of it.

In fact, they were asking for more of it than they were asking just a couple of weeks ago.

On their last visit, they’d asked Congress for $25 billion in bailout loans. A nice round number, $25 billion. So nice and round, in fact, that it sounded like it had been plucked from thin air. And when the auto execs couldn’t — or wouldn’t — provide many details about just how they’d use that money to dig themselves out of the hole they’re in, it sounded even more like it had been plucked from thin air.

Go away, said Congress. Come back when you’ve got something to talk about.

They learned their lesson, the auto execs did. And when they came back this time, they had more details, and they had a number that wasn’t quite as nice and round.

Now, they said, they needed $34 billion.

In Washington, this is considered progress.

“We hate having to ask you for all that money,” the execs kept saying in their mildest, most modest voices. “And we certainly hate having to crawl in front of you and beg you for it while you slap us around for the entertainment of your constituents.

“But if we go down,” they felt compelled to point out, “we’re taking what’s left of the economy down with us.”

Oh.

Too big to fail? Or too clueless to survive? The alternatives aren’t exactly appealing. And hanging over it all, the distinct impression that we’ve been here before. That the auto execs — if not these three, then their predecessors, and their predecessors — have all sworn on a stack of Buicks that they get it, that they know they have to do things differently. Higher quality. Higher fuel efficiency. Faster innovation. Fewer behemoths.

They get it.

Then the market twitches, or the price of gas comes down for a while, or the spotlight moves somewhere else, and it’s just like old times: the bigger, the better, and keep ‘em coming!

“We’re just giving the public what it wants,” the execs insist, as if they have nothing to do with shaping the public’s appetites.

Where’s the guarantee that they won’t pocket all those billions they’re asking for, and go right back to their bloated old habits? The record is less than reassuring.

It’s not that they’re not educable. It’s that they have to learn the same damned thing over and over again.

Rick Horowitz is a syndicated columnist. His e-mail address is rickhoroexecpc.com.