A flawed ballot design may be to blame for Broward County vote discrepancies in the state’s most high profile races, where thousands of voters cast ballots that failed to register their choice in the hotly-contested — and still undecided — race for U.S. Senate, a South Florida Sun Sentinel analysis of voting patterns reveals.

More than 24,900 Broward residents voted for Florida governor but not for U.S. senator, a figure far larger than the margin now separating the two Senate candidates, according to county results updated Thursday evening. The Sun Sentinel found similar discrepancies in other statewide races, where the ballots counted suggest that thousands of voters made the unlikely choice to vote on lower-profile races and bypass the Senate race — a marquee contest and the first one on the ballot.

This unusual pattern appears in no other major Florida county. In other Florida counties, the tallies are as expected, with more voters weighing in on the Senate race than in statewide races of lesser stature.

The issue could be of critical importance as Florida heads toward multiple recounts, with a number of races decided by the narrowest of margins, including the Senate race between Gov. Rick Scott and incumbent Bill Nelson. Republican Scott was leading Democrat Nelson by 15,079 votes as of Thursday evening and the race was heading toward a manual recount.

Broward elections officials were still counting ballots Thursday and county Elections Supervisor Brenda Snipes said she hadn’t investigated the discrepancy yet, but the Sun Sentinel found that Broward’s ballot failed to follow best design practices and may have confused voters.

Counties design their own ballots, and Broward put the Senate race in the bottom left-hand corner, below the instructions. That violates guidelines outlined in a 2007 report by the U.S. Election Assistance Commission, which said ballots with vertical instructions, like Broward’s, “cannot share column space with contests — test voters often overlooked races located immediately beneath vertical instructions.”

Whitney Quesenbery, a ballot expert and co-director of the Center for Civic Design, which seeks to implement best design practices for ballots, said Broward’s ballot design could have caused some voters to skip over the race.

"People can and do make mistakes based on design," she said.

Attorney Marc Elias, who is representing Nelson’s campaign, suggested Thursday that machine counting — not voters overlooking the race — may be the issue.

“I am pretty confident what you are going to see are markings that were not picked up by the machines or a calibration issue that was not registering that part of the ballot," he said.

If Elias is right, the recount could deliver many votes for Nelson in Broward, a county flush with Democrats. But if the issue instead is voters overlooking the race, Nelson will likely be out of luck, according to election experts.

"We can only count what was cast," Quesenbery said.

The largest discrepancies between the governor and Senate votes appear in a group of precincts in southern Broward, specifically in the congressional district of U.S. Rep. Frederica Wilson, the Sun Sentinel found. Wilson did not appear on the ballot because she had already wrapped up re-election after winning the Democratic primary in August.

That meant that on ballots in Wilson’s district, the Senate race was the only race beneath the ballot instructions in the left-hand column. On ballots in Broward’s other congressional districts, the Senate race was followed by a race for the U.S. House.

Here is a look at the unusual vote patterns in Broward, based on numbers tallied as of Thursday evening:

Florida Attorney General: More than 13,900 ballots registered a vote for attorney general but not for U.S. Senator.

Florida Agriculture Commissioner: More than 8,700 ballots showed votes for agriculture commissioner, but not Senator.

Florida Chief Financial Officer: More than 8,300 ballots registered votes for CFO but not Senator.

This wouldn’t be the first time a Florida ballot blunder upended results in an important election. The state has a long history of ballot design issues, including the butterfly ballot in Palm Beach County that took center stage in the 2000 Bush vs Gore presidential election and the 2006 ballot layout in the Sarasota congressional race barely won by Republican U.S. Rep. Vern Buchanan.

"You can go back and check voter intent, but if it is a design problem and people didn‘t see the race to begin with, there is nothing you can do about it,” Lawrence Norden, a lawyer familiar with election law and deputy director of the Brennan Center‘s Democracy Program.

"If this is the cause of lost votes, it is incredibly frustrating that somehow the state hasn‘t gotten its act together to make sure ballots are designed in a way that don‘t cause lost votes. The design was not optimal."

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