Via the Free Beacon, this argument is very on-brand for a Democrat circa 2020. “We’re prepared to spend untold trillions we don’t have on all sorts of politically unviable projects. Why not reparations too?”

The underlying insinuation that racism might be motivating the most left-wing candidate in the race, who’s still a very old white guy at the end of the day, is icing on the cake.

Castro is correct on the basics. Sanders has been chilly to the idea of reparations despite his willingness to break the bank on everything else on the progressive wishlist. How come? Philosophically I think it’s due to him being a class warrior at heart, someone uneasy with the modern left’s romance with identity politics. His skepticism of open borders comes from the same place; why would we depress working-class American wages by allowing a free flow of cheap labor from Mexico? Bernie wants massive wealth redistribution to the lower classes of all races. A special race-based compensation package for historical injustices doesn’t fit comfortably with that.

But there’s pragmatism to it too. Sanders has probably asked himself why the Democratic Party would go all-in on a politically toxic proposal like reparations that would benefit a constituency that already votes Democratic almost unanimously. Reparations is the sort of desperation ploy you’d expect Dems to embrace if a Republican suddenly won, say, 25 percent of the African-American vote in a national election, threatening the left’s monopoly on that demographic. It’s not something you do to try to squeeze a few more percent out of a group that’s already supporting you to the tune of 88 percent or whatever, knowing that some of the suburban whites you just enticed into supporting Democrats in the midterms will run screaming from the idea.

And don’t forget who Bernie’s core supporters are — working-class whites, just like Trump. He’s going to spend the next year making the case that he alone can wrest back those voters from POTUS in Pennsylvania, Michigan, and Wisconsin by beating right-wing populism with left-wing populism. Imagine the reaction among blue-collar whites from counties that have been laid waste by deindustrialization and opioids if reparations got momentum among Dems, replete with lectures about how they owe blacks compensation for their “white privilege.” Bernie would be DOA among the group that’s supposed to put him over the top against Trump. Go figure that he’s not eager to promote this idea.

But he’s also desperate to stay in the good graces of black voters in the Democratic primary given how their support for Hillary hurt him in 2016 and Castro’s point might do him some damage on that score if it gets traction. It’s surprising to see a minor candidate like Castro lob this grenade at him, frankly, precisely because it’s likely to do Bernie more harm than it will do Castro any good vote-wise. It smells to me like a VP tryout for Warren or Harris or whoever: The chief role of a VP nominee in the general election is to attack the other party’s ticket, after all, and Castro’s showing here that he knows how to throw a hard punch — and isn’t afraid to throw it at the progressive idol who’s momentarily leading Warren and Harris. He’s got stalking-horse potential for them.