FiveThirtyEight crunches the numbers and determines what Bernie Sanders needs to win, displaying it in a somewhat confusing chart. This is based on Clinton and Sanders having an equally split national vote, which according to their review of polls, hasn’t happened yet. (Sanders trails Clinton 38% to 50%.)
The next four days will almost certainly be decisive one way of the other for most candidates, Republican or Democratic. On Saturday 2/27, Vermont, Minnesota, Colorado, Massachusetts, and Oklahoma have primaries. Three days later is Super Tuesday with Democratic primaries in Tennessee, Virginia, Texas, Arkansas, Georgia, Alabama, and Kansas.
By Wednesday we will have a much better idea of what the races look like.
In the left column is projected vote margin by state for the winner given an equally split national vote. The right column shows recent polling numbers. Sanders is running behind where he should be.
I must emphasize that these are not predictions of what will happen in these states. Instead, they’re estimates of what would happen if the national vote were evenly divided between Sanders and Clinton (which it isn’t yet). In other words, they tell us whether each state is Sanders-leaning or Clinton-leaning relative to the national average. Sanders will need to beat these targets to have a shot at the nomination, especially since a tie would probably go to Clinton because of superdelegates. As you can see, however, Sanders is currently running behind these benchmarks in states with recent polling.