Mercer County, Pennsylvania
13 heavily Democratic precincts including several minority precincts that usually vote 90% Democratic had most electronic touch screens down all or most of the day. Of those who were able to vote on machines, the machines were malfunctioning and some were unable to vote for the Democratic presidential choice. Most in those precincts were unable to vote with estimates of the number unable to vote as high as 4,000 people.
And of those who did attempt to vote in these precincts, the undervote rate was as high as 75% in the presidential race. The machines were Unilect Patriot touch screens, which also had major problems in other counties. But there were also problems with the backup paper system.
http://www.flcv.com/mercerpa.htmlPennsylvania is in strong competition for the most fruad/malfeasance/problems/suppression - state documentation
http://www.flcv.com/pennsum.htmlBut there were many states with major statewide systematic problems:
http://www.flcv.com/ussumall.html