Did voting problems throw the Florida 13 race?

Did undervotes throw a key U.S. House race in Florida? The evidence is still coming in, and it looks suspicious.

"Undervotes" in election parlance are when the number of votes tallied in a given race are smaller than the total number of people who are known to have voted. Undercounts were a big issue in the 2000 and 2004 elections, where substantial numbers of ballots that were cast didn't register a vote for president. A report by the MIT/Caltech Voting Project (pdf) estimates that up to 30% of undercounts are intentional -- e.g., voters go to the polls, but skip voting in a particular race for whatever reason.

But most undercounts are a result of voting systems problems. And the Sarasota Herald-Tribune reports that could well be the case in Florida 13:

A review of Sarasota County voting results shows that in almost every precinct a high percentage of voters didn't cast ballots in the hotly contested 13th Congressional District, a trend that likely affected the outcome of the race.

Democrat Christine Jennings lost to Republican Vern Buchanan by 368 votes, making it the second closest congressional race in the country.

More than 18,000 voters who showed up at the polls voted in other races but not the Buchanan-Jennings race.

That means nearly 13 percent of voters did not vote for either candidate -- a massive undercount compared with other counties, including Manatee, which reported a 2 percent undervote.

If the missing votes had broken for Jennings by the same percentage as the counted votes in Sarasota County, the Democrat would have won the race by about 600 votes instead of losing by 368, according to a Herald-Tribune review. Even if the undervote had been 8 percent -- more than three times what it was in Manatee -- Jennings would have won by one vote.

While some have speculated that people simply chose not to vote in the District 13 race, many voters say the unusual undervote was caused by badly designed touch-screen ballots, which they say hid the race or made it hard to verify if they had cast their vote.

More than 120 Sarasota County voters contacted the Herald-Tribune to report such problems, almost all regarding the Jennings-Buchanan race.

There's even more evidence that the massive undervote that likely flipped the race is a result of voting technology:

In addition, absentee voters, who didn't have to use the voting machines, had only an estimated 1.8 percent undervote.