Exit polls for 2010 will be available when all polls close in this race.

Methodology

The Election Day polls are based on questionnaires completed by voters as they leave voting places throughout the country. The polls are conducted by Edison Research for the National Election Pool, a consortium of ABC News, Associated Press, CBS News, CNN, Fox News and NBC News.

National data for 2014 was based on questionnaires completed by 19,441 voters leaving 281 randomly selected precincts across the United States, and includes 2,800 telephone interviews with absentee and early voters.

The surveys in 2004, 2006, and 2008 were conducted by Edison Media Research and Mitofsky International; from 1994 through 2002 the polls were conducted by Voter News Service; and in 1990 and 1992 by Voter Research and Surveys.

Direct comparisons from year-to-year should factor in differences in how the questions were asked. For example, before 2000, married was an item on a check list. Protestants have included 'Other Christians' since 1984 and 'Mormon/LDS' since 2004.