I have a new column at CJR on journalistic and fact-checking failures in coverage of Harry Reid’s unsubstantiated claim that Mitt Romney has paid no taxes for ten years. Here’s how it begins:

A week ago, The Huffington Post’s Sam Stein and Ryan Grim published an article repeating Senate Majority Leader Harry Reid’s claim that GOP presidential nominee Mitt Romney hadn’t paid taxes for ten years. Though Reid provided no evidence other than hearsay about what he was told by an unnamed Bain investor (which HuffPost clarified in the ninth paragraph of the story), the story set in motion a controversy that exemplifies how partisans and ideologues exploit the structural weaknesses of journalism and factchecking.

Read the whole thing for more.