Bumps That Linger

Michael McDonald digs into the early voting numbers. Seth Masket has questions:

The growth in early voting is really an interesting and under-developed area for campaign scholars.  Researchers have noted, for example, that when someone of the president's stature comes to down for a rally, it can give him or some other candidate a short-term boost in the polls.  That boost will soon disappear, so it doesn't matter too much.  But if the visit gets thousands of people to walk over to an early polling station and vote, it can matter quite a bit.