This consensus wasn’t based on hard thinking; it was about the attitude politicians were expected to display. As I wrote way back in 2007, proclaiming a Social Security crisis requiring cuts was seen as a “badge of seriousness,” a way of showing how statesmanlike and tough-minded you were.

The candidate I was criticizing, by the way — the guy I said had been “played for a sucker” — was a politician named Barack Obama. But Biden was certainly pulled in by that conventional wisdom, too, so it’s not hard to find old quotes in which he suggested possible Social Security cuts in the name of fiscal responsibility.

But that was then. These days, Biden, like many Democrats, is calling for an expansion of Social Security benefits. That doesn’t make his previous statements irrelevant; he should acknowledge that he has changed his position, and his history on the issue is one reason progressives worry that, if elected, he might fritter away his political capital in vain attempts to reach bipartisan compromise. (His role in passing the draconian 2005 bankruptcy bill, which got Elizabeth Warren involved in politics, is another.)

None of this, however, justifies the Sanders campaign’s lying about recent statements by a man who, after all, may well be the Democratic presidential nominee — and who would, whatever his centrist history, be infinitely more progressive than the current occupant of the White House. And the smearing of Biden reinforces the concerns some of us have about Sanders.

There has always been an ugly edge to some of Sanders’s support, a faction of followers who denounce anyone raising questions about his positions — even Warren! — as a corrupt capitalist shill. Until now, however, you could argue that Sanders himself wasn’t responsible for the bad behavior of some of his supporters.

You can’t make that argument now. The dishonest smears and the doubling down on those smears are coming from the top of the Sanders campaign; even if they aren’t coming directly out of Sanders’s mouth, he could and should have stopped them. The fact that Sanders isn’t apologizing to Biden and replacing the people responsible says uncomfortable things about his character.

I don’t want to go overboard here. While there is a Trumpian feel to some of what we’re seeing from the Sanders campaign, Bernie Sanders is no Donald Trump. As we’ve just seen, there are some real issues with the people surrounding him, but they’re nothing like Trump’s gang of thugs. And in practice a Sanders presidency, like a Biden presidency, would be a vast improvement, morally as well as substantively, on what we have now.

But right now, Sanders and his campaign are behaving badly, and they need to be called on it.

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