If the Democratic presidential race were a poker game, by now you’d have to suspect that Barack Obama’s campaign is dealing from the bottom of the deck: Rarely a day goes by when it doesn’t slap another ace down on the table. The aces in this (possibly strained) metaphor are endorsements, and it often seems as if the Obama operation has an inexhaustible supply at its disposal. In the past week alone, it has announced the support of congressmen from North Carolina and Indiana; the Utah state party chair; the Oklahoma state party’s chief fundraiser; 25 South Dakota state legislators; the owner of the Pittsburgh Steelers; and, not least, The Boss. Some of these endorsers are superdelegates, and thus of no small consequence to the outcome of the race. Others are simply window-dressing, deployed to create a sense of ineluctable momentum in Obama’s direction. But none have the particular resonance of the endorsement that’s coming — unbeknownst to the campaign — a little later today.

The endorsement in question is that of Robert Reich, Bill Clinton’s first Secretary of Labor and a friend of both the former president and his wife for four decades. Around 1 p.m. EST, Reich informs me, he intends formally to declare his support for Obama on his blog.

Now, in one sense, the Reich endorsement comes as no great surprise. For some time, it’s been clear to anyone paying attention that Reich favors Obama. Back in December, in a blog post titled “Why is HRC Stooping So Low?,” Reich loudly and sharply criticized Clinton’s conduct in Iowa and defended Obama’s proposals for health-care and Social Security reform. Two days before the race-charged South Carolina primary, he assailed Bill Clinton’s “ill-tempered and ill-founded attacks” on Obama, arguing that they were “doing no credit to the former president, his legacy, or his wife’s campaign.” And all throughout the primary season, he has spoken and written of Obama’s candidacy with evident admiration and enthusiasm.

But Reich insists that the endorsement does indeed come as a surprise — to him. As we chatted in Washington, where Reich had come from Berkeley, where he teaches, to give a speech and meet with some Democrats on Capitol Hill, he explained that, despite the criticisms he’s made of the Clintons (“I call it as I see it”), he had planned to refrain from offering an official backing for Obama out of respect for Hillary. “She’s an old friend,” Reich said. “I’ve known her 40 years. I was absolutely dead set against getting into the whole endorsement thing. I’ve struggled with it. I’ve not wanted to do it. Out of loyalty to her, I just felt it would be inappropriate.”

So what’s changed? I asked Reich.

“I saw the ads” — the negative man-on-street commercials that the Clinton campaign put up in Pennsylvania in the wake of Obama’s bitter/cling comments a week ago — “and I was appalled, frankly. I thought it represented the nadir of mean-spirited, negative politics. And also of the politics of distraction, of gotcha politics. It’s the worst of all worlds. We have three terrible traditions that we’ve developed in American campaigns. One is outright meanness and negativity. The second is taking out of context something your opponent said, maybe inartfully, and blowing it up into something your opponent doesn’t possibly believe and doesn’t possibly represent. And third is a kind of tradition of distraction, of getting off the big subject with sideshows that have nothing to do with what matters. And these three aspects of the old politics I’ve seen growing in Hillary’s campaign. And I’ve come to the point, after seeing those ads, where I can’t in good conscience not say out loud what I believe about who should be president. Those ads are nothing but Republicanism. They’re lending legitimacy to a Republican message that’s wrong to begin with, and they harken back to the past twenty years of demagoguery on guns and religion. It’s old politics at its worst — and old Republican politics, not even old Democratic politics. It’s just so deeply cynical.”

The Clinton campaign will, no doubt, shrug off the Reich endorsement of Obama. (And hey, who knows, maybe James Carville will get into the act and declare Reich a Benedict Arnold!) They will say that it’s unlikely to move any votes, and that, since Reich is not a superdelegate, it does nothing tangible to move Obama even one inch closer to the nomination.

All of which is true enough, as far as it goes. But beyond the bald fact of Reich’s support for Obama, the Clinton campaign should pay heed to the reasoning behind it. In his disgust with Hillary’s increasingly harsh tactics, Reich is hardly alone. Indeed, the feeling seems to be spreading more broadly in the party with every passing day. It’s been clear for some time that Hillary’s attacks on Obama were driving up her negatives. You could certainly argue this might be a price worth paying if those attacks were amping up doubts about him. But it’s hard to see any logic — or even sanity — in the tactic if the result is to drive even people who once regarded Hillary dearly into Obama’s arms. — John Heilemann

Related: Superdelegates Making Howard Dean Just Want to Scream [NYM]

Gibson and Stephanopoulus Criticized After Debate [NYM]

How Barack Obama Lost The Debate — And Whether It Matters [NYM]

Is John McCain Bob Dole? [NYM]

Hillary Clinton and the Feminist Reawakening [NYM]

For a complete and regularly updated guide to presidential candidates Hillary Clinton, Barack Obama, and John McCain — from First Love to Most Embarrassing Gaffe — read the 2008 Electopedia.