2.8 Million votes were cast in the election (2.8
2004 Governor's Race)
out of 3.1 million registered voters (
2004 Election total registered voters statistics - states compared - StateMaster Government) which makes the statement that more votes were cast than voters inaccurate.
Washington State had an absentee voter system that made it very easy for voter to use, and allowed the large vote turnout. In King county over 60% of the voters voted absentee!
I personally think that we ought to start to allow voting on the internet. I think this would bring the participation back up to the 70% or 80% level, not at the 50% level we are at now.