Why does different sources show a different popular vote tally. This happens even in the most recent elections such as 2012, 2008, etc.
I've complied the results from 3 sources:
-
- a compilation of the official, certified federal election results obtained from each state’s election office and other official sources (quoted)
-
- The site has been used a reference for U.S. election and political data by major media outlets. Leip's Atlas has been cited as a "preferred source for election results" by statistician and political pundit Nate Silver. (quoted from Wikipedia)
National Archives and Records Administration
- These results are taken from each state's Certificate of Ascertainment. They will become available as the Certificates of Ascertainment are received and verified for completeness and accuracy. (quoted)
Both the FEC & archives.gov describe their results as official, yet they still differ. The difference ranges from hundreds to millions.
+------+-----------+-------------------+-------------------+--------------+
| Year | Candidate | Federal Elections | Dave Leip's Atlas | archives.gov |
| | | Publication | | |
+------+-----------+-------------------+-------------------+--------------+
| 2012 | Obama: | 65,915,795 | 65,918,507 | 65,446,032 |
| | Romney: | 60,933,504 | 60,934,407 | 60,589,084 |
| 2008 | Obama: | 69,498,516 | 69,499,428 | 69,297,997 |
| | McCain: | 59,948,323 | 59,950,323 | 59,597,520 |
| 2004 | Bush: | 62,040,610 | 62,039,572 | 60,693,281 |
| | Kerry: | 59,028,444 | 59,027,115 | 57,355,978 |
| 2000 | Bush: | 50,456,002 | 50,462,412 | 50,996,582 |
| | Gore: | 50,999,897 | 51,009,810 | 50,456,062 |
| 1996 | Clinton: | 47,402,357 | 45,590,703 | 47,400,125 |
| | Dole: | 39,198,755 | 37,816,307 | 39,198,755 |
| 1992 | Clinton: | 44,909,889 | 44,909,806 | 44,908,254 |
| | Bush: | 39,104,545 | 39,104,550 | 39,102,343 |
+------+-----------+-------------------+-------------------+--------------+
So,
- Why is this so?
- Which source can be considered the most "official"?