Call him whatever you want — but don’t call him inconsistent. Bernie Sanders has been on message for more than half a century. And while liberals scramble from scandal to scandal under President Trump, Sanders is like a slow-moving tank rumbling through enemy lines.

And it’s his powerful message that carried Sanders from obscurity to become America’s most popular politician. His 2016 presidential campaign started with some haphazard remarks delivered to an empty National Mall. Bernie stood calmly behind a podium, said a few words about inequality, and then walked out of frame as if nothing had happened.

His political life started in obscurity too, in the dying remnants of the Socialist Party of America. He threw himself into civil rights and labor struggles through the 1960s, but by the end of the decade the native New Yorker retreated to rural life in Vermont. His first foray into electoral politics there yielded results familiar to the American left — 2.2 percent of the vote, in a 1972 Senate special election.