As Donald Trump caught up with Hillary Clinton in the polls over the past two weeks, the Bernie Sanders campaign has reiterated its last-ditch argument to win over superdelegates and secure the nomination: The Vermont senator is walloping Trump in the polls by over ten points, in contrast to Clinton’s dead heat. To counter this increasingly messy fact, several Clinton boosters in the media have dusted off an old talking point: that Sanders hasn’t been properly “vetted”—thoroughly examined for political faults—rendering the polls meaningless.