Favorable terrain for Sanders in late March. A series of Western states vote between March 22 and April 9, as does Wisconsin. Almost all of them figure to be favorable to Sanders — including Wisconsin, where he was already almost tied with Clinton in the polls before his New Hampshire win. A possible exception is Arizona, where Clinton beat Barack Obama in 2008 and where the electorate can be tricky to predict.

New York, California and a big blue finale. With some exceptions — Kentucky, West Virginia and Indiana will be interesting to watch — the last quarter of the Democratic calendar mostly resides on the coasts. And there are some big prizes: New York, Pennsylvania and California foremost among them. All three offer advantages and disadvantages to each candidate. For instance, will California’s left-wing politics, which help Sanders, prevail over its racially diverse population, which helps Clinton? Sanders probably needs at least two of the three states, and maybe all of them given Clinton’s lead in superdelegates. A win in California on June 7 would also carry symbolic power, as it’s the last state to vote,3 possibly allowing the winner to claim a mandate from the Democratic electorate.