Every Democratic candidate would need to win more than 50 percent of the popular vote to win the electoral college. But exactly how much varies by candidate: Warren makes it to 270 electoral votes first, with about 50.7 percent of the popular vote, followed by Buttigieg, then Kamala D. Harris, and finally Joe Biden and Bernie Sanders. These estimates are not perfect; though Warren wins first most of the time, she isn’t guaranteed to do so.

To understand these patterns, let’s look at two key sets of swing states: the Rust Belt states of Michigan, Pennsylvania and Wisconsin, which were key to Trump’s victory in 2016; and the Southwestern states of Nevada and New Mexico.

The graph below shows how well a Democrat must do nationally to win back the Rust Belt. On average, Democratic candidates poll 7.4 percent lower among whites than among the general population. But Buttigieg polls only 6.4 percent lower. As a result, he can usually win these states with 49 percent of the national popular vote — and so would win more electoral votes, on average, than his competitors.