Just look at this list from The Drudge Report:
If you remember, there was a time (prior to 2000) when both parties and their voters could vote almost without incident. So why is it different now? One reason: Al Gore’s refusal to accept defeat in 2000. Since then, vote fraud allegations are made as a matter of course. It’s part of the electoral game now. The damage this does to the legitimacy of elections is incalculable. Thanks, Al.