None of these excuses really apply for the primaries on Tuesday — Idaho, Michigan, Mississippi, Missouri, North Dakota, and Washington. Sanders is currently behind in most of these states, but not so far behind that his voters should think it is hopeless. His potential supporters in these primaries should know he can still win and how much their votes matter. The large black population in Mississippi is a real challenge for Sanders, but the other states are theoretically winnable. In Idaho and Washington state, Hispanics, a group Sanders has done very well with, are the largest minority group, making up just over 12 percent of the population. Michigan has a large union population, which the Sanders campaign has aggressively courted. In 2016, Sanders won the North Dakota caucus overwhelmingly although this year the party switched to a more open “firehouse caucus.”

Equally important, the choice between candidates has never been so simple. With all the other candidates out of the race, the stakes are clear and the choice truly binary. There are no questions about strategic voting and reaching delegate thresholds or tactical arguments about the best way to achieve progressive goals. Biden has always been one of the most conservative candidates in the race, and Sanders the most progressive. Sanders and Biden offer very different visions of the country and support very different policies. On issues ranging from health care to trade to foreign policy, they are the two Democrats who have been furthest apart. Biden’s message is a return to normalcy while Sanders’ message is a big change. For the first time, Sanders is not just trying to get voters to turn out for something — he can also pitch them on turning out against something.