On Saturday afternoon the Washington Post’s Jonathan Capehart walked back a widely circulated “debunking” of a photo of Bernie Sanders from his days at the University of Chicago during the civil rights sit-ins of 1962

The official answer, given Capehart’s finger-wagging tone, is that the truth is important and he’s simply trying to correct the record. In fact, it’s an attempt to undermine the two things Sanders needs more than anything right now: people to trust him and African-American voters to like him. Perhaps Capehart believed using his prime op-ed column inches to resurrect a three-month-old story to shame a few Sanders partisans on Twitter was a good use of his pundit capital, but it’s more likely he just wanted to further muddy the waters on Sanders’ civil rights record in the runup to the largely African-American South Carolina primary.

Shouldn’t he have done his reporting and fact-checking before he accused the Sanders campaign of deliberately spreading false misinformation about Sanders’ civil rights record?