First of all: Did this second round of debates change anything?

Maybe. We’ll see the polls starting over the weekend. If anything, my guess is that Joe Biden may tick down, and Elizabeth Warren may tick up, although who knows about these things? Will any of the second-tier people gain ground? Perhaps. But earth-shaking change seems unlikely; ratings seems to have been really low (8.7 million on the first night, I don’t yet know about the second), and we didn’t learn a lot about any of them that we didn’t know.

I did however learn a really interesting thing: Barack Obama was apparently a Republican.

Yes, Biden—trying when he can to stay above the primary fray and run directly against Donald Trump—is the front-runner. The other candidates are bound to hit the front-runner. He needs to be able to take it.

But Wednesday’s debate ended up being far more about Obama’s record than Trump’s. In fact, except for the rehearsed opening and closing statements, Obama came in for more criticism than Trump.

This is absolute madness. And it’s political suicide.

Obama has a 97 percent approval rating among Democrats. No one has a 97 percent approval rating among anybody. Tom Brady probably isn’t at 97 among Patriots fans.

And the way to rally and unify the party and get everybody on board in the effort to remove a racist authoritarian from the White House is to point out every single thing that Obama did wrong? Nothing will dispirit the Democratic rank and file more than that.

The party is too diverse to say such-and-such a person is “the typical Democrat,” but consider these facts. More than half, according to a recent Pew typology study (pdf here), make less than $50,000 a year. Two-thirds are not college graduates, and more than one-third have a high-school education or less. These are working people who have difficulty making ends meet.

I’m not going to generalize about their political views, but I will make two assertions with some confidence. One, they want to hear ideas that will help them directly in their lives, and two, they admire Barack Obama.

I kept listening to all those attacks on Obama’s record on immigration and criminal justice and all the rest thinking about these people watching and probably wondering what was going on here. The Constitution is being torched. The house is burning to the ground. And the villain Wednesday night was Obama?

Cory Booker at one point said to Biden that “you can’t have it both ways,” meaning of course that Biden can’t invoke the Obama association hoping to remind people of the good without accepting some of the bad. That’s fair.

But you know who else can’t have it both ways? Every one of the rest of them. These people were all huge Obama supporters. I’m sure they offered muted criticism here and there, but there was a quality to Wednesday night’s debate of many of these Democrats hinting that they were always on to the guy.

No. Can’t do that. Julian Castro was in Obama’s Cabinet. Funny, I don’t remember him resigning over Obama’s immigration policies. And most of them praised not just Obama at the time, but Biden himself. Check out this tweet:

On top of that, these people all have imperfect records, too. We began to see that last night with respect to Kamala Harris, who as California attorney general kept nonviolent inmates incarcerated in prisons the Supreme Court had ruled were overcrowded, arguing they were needed as a cheap labor source. Cory Booker was pretty law-and-order as mayor, and worked with Chris Christie to advance charter schools, and has spent the vast majority of his Senate career being a friend of Wall Street.

Understand me: My point is emphatically not to make a comparative defense of Biden. My points are two.

First, that everybody who’s been in public life, in positions carrying life-and-death responsibility as mayors and state attorneys general and even vice presidents sometimes are, has made difficult decisions among a series of options that ranged from bad to worse. Booker should have worked with Christie—Booker was the mayor of his state’s largest city, and Christie was his governor! But note how sinister “Booker worked with Trump lover Christie” can be made to sound in a sentence or tweet.

Second, that if this primary gets too bogged down in that, it will bring way too much bad blood to a boil, and the nominee will stagger into the general election campaign. In defining any candidate’s past actions by the standards of today’s left-most criteria, everybody will end up looking bad. The debates will yield nothing but video clips of attacks—character attacks—that will make fantastic ads for the Trump campaign.

The Democratic Party, unlike the Republican Party, is a party of change; of constant striving for more progress and social justice, as Lawrence O’Donnell pointed out Wednesday night after the debate. A commitment to that is one of the key reasons Democrats are Democrats, and I mean everyone, from Rashida Tlaib to John Delaney. That, obviously, is a good and necessary thing.

But that commitment cannot require a rejection of the past. That is dogma and intolerance, and that way lies intellectual darkness.

Democrats have three living ex-presidents, two of whom were incredibly successful. One of those two, Bill Clinton, is the most economically successful post-war president out of all 13 of them. He’s already persona non grata. I get why. But he has been all but banished. I’d be surprised if he even shows up at the convention.

And now the candidates are starting to do the same to an ex-president who is beloved by nearly all of the party members. Stop this now. Remember who you’re really running against. And just as importantly, remember who you’re running to serve and represent, and the huge and diverse coalition, Tlaib and Delaney and everyone in between, you’re going to have to weave together to win. As a wise man once said, do the right thing.