Voter Id laws, selective purging of rolls, rank intimidation of immigrants and other groups, altered registration listings, relocated voting sites, reduced voting hours, reduced early voting periods and locations, severely reduced number of voting sites in certain districts, voter rolls purged in error by "inaccurate" data or by companies specializing in removing un-desirable voters, or older voters allegedly removed or incorrectly registered due to age or prior voting attendance, previously registered democratic voters curiously listed as independent or republican, gerrymandered districts, new registration forms altered after the fact or simply dumped in the trash by paid agents, former felons removed "erroneously" due to name matching software that in fact doesn't match names accurately......
It seems like nearly every week we hear of a new wrinkle, or several of the old ones. It is not due to errors of bureaucracy. It happens because someone is enabling it on large and small scale as often as they can get away with it. It happens because each state is responsible for the rules and how they are applied. Unlike any other Democracy on earth we do not have federal rules and laws making the process correct and identical and transparent in every district, precinct and state. It happens because it favors those who win best by making the voters unable to vote. Currently that is most often the Republican Party. However there are reasons to wonder whether some of this was recently practiced to disable certain democrats from voting in some of the primary elections, too.