Before people start crying that partisan politics, cheating state election officials, and political operatives are to blame, it is important to note that the New York Times found that "the actions do not seem to be coordinated by one party or the the other, nor do they appear to be the result of election officials intentionally breaking rules, but are apparently the result of mistakes in the handling of the registrations and voter files as the the states tried to comply with a 2002 federal law, indented to overhaul the way elections are run." The 2002 federal law in question is the ironically named Help America Vote Act of 2002, which was designed to provide federal money to help states modernize their voting systems. However, buried in the bill was a relatively innocuous and highly vague subsection that required that if states received Federal money under this program they would also have to ensure that their registered voter rolls were accurate and modern and that states create statewide voter rolls. Previously, these voter lists were kept on a local level. It is the combining these local rolls up to the state level that is probably causing all the problems since it is a huge process and removes the local factor of knowing who lives in the area, who has similar names, etc.
In the past, state voter resignation rolls are notoriously out of date. In fact the organizations that have the most up to date valid voter registration lists are of course the two major parties. They use these lists to contact likely voters of their party to make sure they have ways to get to the polls, know who the party would like them to vote for, etc. and since they use these lists on a regular basis to figure out their parties position in a state, they regularly update them when they find people have moved out of the state, died, or been convicted of a felony. While only the state election rolls are valid in determining who can and cannot vote on election day, state election officials have none of the incentives that parties do to make sure that their voter registration rolls are up to date. As a result, in the past, registered voter rolls would regularly have voters listed who had moved out of the state or died.
In 2002, the republicans were on a mission to end what they conceived as nation wide voting fraud. As a result, between 2002-2005 we saw lots of new voter identification laws crop up in many republican controlled states and as we have already said at the Federal level we had the Help America Vote Act of 2002. The key aspect of all of this is that with a few exceptions states are free to conduct elections and register voters how ever they want. So, when the conditions of the Help America Vote Act of 2002 are put into play, they have a slightly different effect in each state, based on how that states existing election law is set up. In some states it may require updating of lists in others that have electronic record keeping it may require no action. The net result is that since the Help America Vote Act of 2002 is so vague as to what exactly states have to do to their voter registration rolls to qualify for Federal aid, that many states have taken actions that are not required and in fact my actual violate existing federal election law by incorrectly disenfranchising qualified voters.
I will refer you to the New York Times article for details about what states are exactly doing that is illegal, but the key result is that the New York Times found that for every voter that has been added in some of these swing states, two have been removed from the rolls. Now, it is important to point out that such a ratio could reflect how out of date the rolls are and that there really are a large number of people who have left or have died and thus shouldn't be on the rolls. However, considering the advantage Obama has had in registering new voters, even if the purging was random of qualified voters, its effect is likely not to be since there are now so many newly registered democrats. The actions taken by these states has to be of concern and warrants an investigation by the FEC and state officials to ensure that all qualified voters are able to vote on Nov 4th.
Beyond this election, even though I am a strong supporter of federalism as an important check on Federal power, we must consider nationalizing our election systems so that we have a common set of rules and procedures for how we vote in this nation. As long as we have 50 different systems with little oversight and transparency the risk for disenfranchising legal voters is too high.