In 2020, the United States has a historic opportunity: it can elect its first democratic-socialist president and put itself on the path toward becoming a humane, peaceable, and environmentally sustainable country. It’s obvious that a Bernie Sanders presidential campaign would be a huge boon to democratic socialism. His success would produce a tectonic shift in the country’s politics. The range of acceptable ideas would shift significantly to the left, and a Sanders presidency would make democratic socialism a commonplace idea overnight.

But presidents cannot get anything done on their own. This was one of Barack Obama’s most serious mistakes: when he got elected, he disbanded his organizing apparatus, and he never built the kind of lasting grassroots coalition necessary to see through even a tepidly liberal political program.

A democratic-socialist president needs a movement behind them. They also need a Congress that is as far to the left as possible. That’s why, if socialists are going to make a Sanders presidency succeed, we must stake out an ambitious goal for 2020: there should be no election, at any level, without a socialist candidate running.