understand the difference

voter fraud

http://www.firedupmissouri.com/squelching_the_nun_vote

election fraud

http://itpolicy.princeton.edu/voting/

the first is hardly an issue (except in chicago, vote early, vote often)
the second is pervasive, think florida 2000, ohio 2004

the remedy for the first, stops people from voting
the lack of investigation of the second, gives us the worst president in history