As the Democratic Party gears up for its third debate next month, there is a continuing perception that the candidates are disconnected from the average voter, with conservative commentators asserting that the front-runners are pushing policies that most Americans don’t support.

But this criticism is valid only if three assumptions hold: First, that Democratic politicians are strategic imbeciles; second, that the candidates are truly embracing purity at the expense pragmatism; and third, that majority support is required to win a presidential election. Each of these suppositions is questionable.