Tens of thousands of eligible voters in at least six swing states have been removed from the rolls or have been blocked from registering in ways that appear to violate federal law, according to a review of state records and Social Security data by The New York Times. The actions do not seem to be coordinated by one party or 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 states tried to comply with a...