Bernie Sanders has promised to break up the country’s biggest financial institutions during his first year in office. It’s one of the central tenets of his campaign, and last week he was asked about how he’d do that in an interview with the editorial board of the New York Daily News. He’s now being criticized for seeming vague and evasive. But is the criticism fair? As the California primary nears, we will periodically examine the promises candidates are making. Today: How would Sanders break up the big banks?