And that assumption has been proven correct too many times to dismiss it.
Not only hasn't it (ever) been proven correct, but it can't be: there's no way to "prove" anything about 110 million voters by waving a magic wand over a clustered sample of a few thousand.
"What about the Ukraine?", as the urban legend goes:
A key part of the media game has been the claim that Yushchenko won according to "exit polls". What is not said is that the people doing these "exit polls" as voters left voting places were US-trained and paid by an entity known as Freedom House, a neo-conservative operation in Washington. Freedom House trained some 1,000 poll observers, who loudly declared an 11-point lead for Yushchenko. Those claims triggered the mass marches claiming fraud. The current head of Freedom House is former CIA director and outspoken neo-conservative, Admiral James Woolsey, who calls the Bush administration's "war on terror" "World War IV". On the Freedom House board sits none other than Brzezinski. This would hardly seem to be an impartial human-rights organization.
http://www.atimes.com/atimes/Central_Asia/GA20Ag01.htmlBut not all observers of Ukraine's "Orange Revolution" are so elated. Instead of democracy's advance, some see a U.S.-funded, White House-orchestrated conspiracy to undermine Ukrainian sovereignty, weaken Russia's sphere of influence and expand Washington's imperial reach. These skeptics range from presidents Vladimir Putin of Russia, Alexander Lukashenko of Belarus and Hugo Chavez of Venezuela to Republican Rep. Ron Paul of Texas, columnist Patrick Buchanan, and left-wingers in the Nation and the Guardian.
http://www.washingtonpost.com/ac2/wp-dyn/A15131-2004Dec20Meanwhile, in the UK:
Shy Tory Factor is a name given by British Opinion polling companies to a phenomenon observed in the 1990s whereby the share of the vote won by the Conservative Party in elections was substantially higher than the proportion of people in opinion polls who said they would vote for the party. The Conservative Party is often referred to by its previous name 'Tory'.
In the 1992 general election, the final opinion polls gave the Conservatives between 38% and 39% of the vote, about 1% behind Labour. In the final results, the Conservatives had a lead of 7.6% over Labour. As a result of this failure to 'predict' the result, the Market Research Society held an inquiry into the reasons why the polls had been so much at variance with actual public opinion. The report found that 2% of the 8.5% error in the party lead could be explained by differential refusals to be interviewed by Conservative voters; it cited as evidence for this factor the fact that exit polls on election day also underestimated the Conservative lead, when they could not be affected by sampling error.
http://en.wikipedia.org/wiki/Shy_Tory_FactorBut since the exit poll hoax isn't particularly logical, the argument necessarily skips to the next magical belief. Take your pick:
1) "But Bush did better in Diebold precincts!" (except that he didn't, and it belies the circular assumption that machines=fraud ergo fraud=machines, putting aside the Florida 2000 chad fiasco)
2) "But all the pre-election polls said Kerry landslide!" (except that they didn't, in fact * led the majority of them, unless you
cherry-pick only Kerry leaning polls)
3) "But exit polls are always correct!" (back to square one)
I understand the appeal of the "theory" (never having to get off your butt or apologize for ~51% of your brethren), but the hoax is a self-fulfilling prophecy: once you believe you're a hapless victim of fate, that's exactly what you become. If you "know" fraud occurred but can't be bothered to find out why, when, or where ("the exit polls got the answer I like, that's all that matters"), then you merely contribute to apathy and the suppression of Dem turnout (not to mention the fact that disenfranchised/purged voters don't even appear on exit polls, so the "exit poll=right answer" hypothesis assumes that institutional racism is a valid selection criteria).