More on The West Wing’s cancellation:

Since the new year, Wells has been writing the two-part episode in which Leo will die of a heart attack. The cantankerous politician with a soft side and a sense of humor survived a heart attack last season, an illness Wells said he would have never written for the character had they known Spencer would be prone to it. The episode in which Leo dies, five days before the election, will air on April 2, Wells said….

When the show’s writers began researching how the government would handle the death of a vice presidential nominee just before an election, they were surprised to learn there was no constitutional provision for it. Based on the advice of election attorneys, Wells decided that Leo McGarry’s name will remain on the ballot and if Santos wins, he will then appoint a vice president after his inauguration.