Record numbers of voters are turning out for today's election, which is bound to make history, whichever side wins. We look at issues, voting blocs and possible problems in crucial battleground states. Also, networks' plans for exit polls, and voters in various states face a total of 153 ballot measures, some on controversial subjects. Will they bring out additional voters that could influence other elections?
Banner image: Voters stand in line at their polling place before dawn in Phoenix, Arizona. Photo: David McNew/Getty Images