Where did Bush's extra votes in Broward County come from? A little "What If?" analysis shows some real improbabilities. Kerry's margin might have been reduced by as much as 54,000 votes in Broward county alone, with no obvious reasons why.
Here's a small spreadsheet that projects Presidential votes for Broward County in 2004 based on the results in 2000 and new voter registrations since then.
1. Start with a base of voters who voted for Bush, Gore, or others in 2000
2. Assume that about 75% of newly registered voters actually voted, and that they voted for the party they registered for
3. Assume that Independent and minor party voters voted for Bush or Kerry according to exit poll percentages (57% of Independents went for Kerry)
The resulting projections gave Kerry 68% of the vote and Bush 31% which is very close to the results from 2000 (Gore 67%, Bush 31%). The actual results in 2004 were Kerry 64%, Bush 35%.
Overall it appears that the actual 2004 results show a Kerry margin that's about 54,000 votes too small.
I tried to explain the Bush increase by tweaking some of the inputs and assumptions.
If you alter the propensity of independent voters to go for Bush to 92% vs. 8% for Kerry it gets Bush 243,000 votes in Broward. This is way out of whack compared to the exit polls showing only 41% of Florida Independents voted for Bush.
You could also suggest that about 27,000 Democrats -- about 6% of Gore's 2000 total -- switched sides to vote for Bush, but again the exit polls don't bear this out. Exit polls show that an extra 1% of Democrats voted for Bush in 2004 compared to 2000. That might get Bush an extra 4,500 votes in Broward, nowhere near 27,000. In addition Republicans were indeed more loyal to Bush this year according to the exit polls, voting for him 93% instead or 91% in 2000. Let's give him the extra 2%, giving him about 3,500 more votes. We're still nowhere near explaining the 27,000 "party switcher" votes.
This is a simplified analysis of course. But it offers one more data point supporting the theory of vote manipulation in Florida counties that use electronic voting machines.
A total swing of 54,000 votes in a single county is a big variation. Multiply this by a few more counties and you could even overcome Bush's 375,000 margin of victory in Florida. I have no doubt that the other electronic voting counties in Florida will show similar, inexplicable vote increases for Bush. I'll let you know what I find out.