Donna Brazile’s revelation that the Hillary Clinton campaign literally bought control of the Democratic National Committee in 2015, months before the first 2016 primary, comes as Democrats are still struggling to decide why they lost.

Note, by the way, that last year’s shocks went beyond Donald Trump’s capture of Michigan, Wisconsin and Pennsylvania, and so the White House: Democrats also failed to win control of the Senate, which they’d thought was in the bag.

So it’s not just that Clinton was a terrible candidate running a big, fat and dumb campaign: Without realizing it, the whole party lost touch with a huge swath of the nation.

But what to do about it? Party strategist Stanley Greenberg notes that “the Democratic Party today is divided over whether it wants to focus on the economy or identity” — that is, identity politics.

Much of the base wants to go “full Bernie,” and embrace free college and national health insurance. Yet this ignores the fact that Bernie Sanders did so well in the primaries mainly because Clinton was the same horrible candidate she’s always been.

This wing of the party thinks President Barack Obama was too centrist. Hmm: Is that why the party lost 14 governorships plus nine Senate and 60-plus House seats on his watch?

Then, too, you hear quiet talk from other Dems of how the “Bernie Bros” are sexist and even a bit racist. Why, after all, didn’t a proudly left-wing candidate find a way to bring the energy of the Black Lives Matter movement into his campaign?

Current DNC chief Tom Perez, a former Obama cabinet member, is firmly in the identity-politics camp. That’s brought home by the leaked internal DNC e-mail warning against filling any more tech jobs with “cisgender straight white males . . . since they’re already in the majority” — in the tech department.

Meanwhile, Perez last month purged several top Sanders supporters from DNC leadership positions. Control of the vital Rules and Bylaws Committee seems lodged in Hillaryite hands.

A year after their historic defeat, in short, Democrats are getting set to rinse and repeat.