I think they had 20,000 votes cast in 2012, and not a single vote was for Romney?
Not even one? James O'Keefe's assertion was that that alone should ring alarm bells for voter fraud.
The problem appears to be precinct level fraud with some kind of ballot stuffing. There should always be a few votes for Romney made in error, people who never heard of Obama, or whatever. But with zero there is likely some systematic fraud by the precinct personnel.