by Theodore de Macedo Soares
According to the exit polls conducted by Edison Research, the Democratic Party Senate candidates won three Senate seats that went to the Republican candidate in the computerized vote counts. With these additional seats, the Democratic Party would have regained control of the Senate—51 seats to 48 for the Republican Party and one Independent (caucuses with the Democratic Party).
Edison Research conducted exit polls in only 28 states in the 2016 general elections. Senate seats were contested in 21 of these states. The contests in 20 states featured races between Democratic and Republican Party candidates. Discrepancies between the official vote count and the exit polls favored the Republican Party candidate in 17 states. In 12 of these states the discrepancies were beyond the exit poll margin of error. See table and notes below.
The link Exit-Polls_2016-US-Senate-Elections.zip contains the exit polls downloaded from CNN shortly after the polls closed in each state. If using these files please credit www.tdmsresearch.com and Theodore de Macedo Soares as the source and most importantly cite the article that shows the results of these exit polls: http://tdmsresearch.com/2016/11/15/2016-us-senate-elections/
 Exit polls (EP) conducted by Edison Research and published by CNN shortly after the closing of polls for the state and downloaded by TdMS. Jonathan Simon downloaded MO EP. Edison Research conducted exit polls in only 28 states including 21 states with senate races. Exit poll results are derived from the gender category–the proportion of men and women voting for each candidate. As these first published exit polls are altered/adjusted to conform to the unverified computer vote counts, the discrepancies shown above are adjusted to near zero in the final EPs.
 New York Times reported vote count. Last updated on November 21, 2016. http://www.nytimes.com/elections/results
 The margin columns subtracts the Democratic Party Senate candidate totals from the Republican Party Senate candidate. A Republican Party candidate win is shown by a positive sign and a Democratic Party candidate win by a negative sign. Due to rounding some totals may appear slightly inconsistent.
 Note that the Margin of Error (MOE) is for the differences between the two candidates (at 95% CI). This MOE is about double the usual MOE for each candidate. MoE calculated with multinomial formula discussed in sections 2 and 4 in: Franklin, C. The ‘Margin of Error’ for Differences in Polls. University of Wisconsin, Madison, Wisconsin. October 2002, revised February 2007. Available at: https://abcnews.go.com/images/PollingUnit/MOEFranklin.pdf
 In California, the two candidates were both Democrats: Kamala Harris (represented in the Democratic Party columns) and Loretta Sanchez. http://www.weeklystandard.com/californias-no-republican-senate-race/article/2004578
Update: November 17, 2016. Revised table with updated vote counts. A transcription error in the previous table erroneously indicated an exit poll win for the Democratic Party in Florida. Deep apologies. All work has now been triple-checked.
Update: November 21, 2016. Vote counts updated. Only California vote count changed slightly. The New York Times will next update their vote totals once states certify their elections.
Update: November 26, 2016. Exit polls used for the table above made available for download.