The option of using a vote by mail option for a “do-over” primary election in Florida and Michigan is gaining traction. Florida Senator Bill Nelson has been urging the option on the state, and DNC Chair Howard Dean recently praised it as a way out of the current morass.

Like any voting system, vote by mail has benefits and flaws. And like any election system, voting by mail needs to be evaluated on the empirical evidence, not on hopes and anecdotes. I’ve been studying vote by mail for four years now, first as Director of the Early Voting Information Center and now as a consultant to the Pew Charitable Trust’s Make Voting Work initiative. In this case, the empirical evidence on how voting by mail operates argue in favor of using it for the revote. It is the best of the worst options available, but only for Florida. Michigan is not ready to conduct a statewide vote by mail election.

Voting by mail attracts a large, representative electorate to the polls. It increases turnout by two to five percent when compared to precinct place voting. And the vote by mail electorate looks no different from the precinct place electorate. Ironically, this is often pointed to as a flaw of vote by mail: it does not expand the electorate into disempowered segments of the citizenry, such as younger, lower income, or minority populations. For a revote, however, the “do-over” will look much like the original primary, which is a good thing.

Vote by mail will not help or harm either candidate. Bob Stein of Rice University has shown that early voting systems such as vote by mail help well-funded campaigns without respect to party, because campaigns have to engage in a two-week, not a two-day, mobilization effort. In this election, both candidates have more than enough resources to mobilize Floridians.

What about the most commonly cited flaw of voting by mail: that it is more prone to fraud? It is true that absentee ballots are the most common source of election fraud. But the actual occurrence of fraud is microscopically small, and when we do find evidence of fraud, it is in local races, such as in the 1997 Miami mayor’s race. Local races are where a few hundred ballots can make a difference. In a large state contest being heavily contested by two national campaigns and scrutinized by the national media, the possibility of fraud is nearly zero.

Two barriers remain, a surmountable for Florida, but an insurmountable one for Michigan.

The first is: who pays? Both Florida and Michigan argue that they are not to blame for the current morass, but these claims ring hollow. But their political leaders knew what they were doing when they moved up their primaries and what they gambled. The national party has called their bluff, and it’s time for the states to pay up. In doing so, both states arguably get precisely what they wanted in the first place—the two states will be the most most important contests in 2008.

Still, with two campaigns raising more than a million dollars a day, it seems unfair not to have the candidates help as well.

I propose a Solomonic solution: split the cost three ways. The states cover one third of the cost, and the campaigns cover the other two-thirds. The bill for the Florida revote will be less than $8,000,000. It ain’t cheap, but democracy never is.

What about Michigan? Can they run a vote by mail election? The answer is almost certainly “no.” Michigan elections are administered by 83 county clerks, 274 city clerks and 1,242 township clerks (Florida has 67 counties), which is bad. Michigan uses paper ballots, which is good, but has not fully gone over to optical scan, which is bad.

It gets a lot worse. Michigan currently requires an excuse to vote absentee, so the state has no infrastructure in place to deal with high levels of absentee balloting. Putting in place in two months the specialized infrastructure required to process the ballots, such as envelope sorters and slicers and signature verification systems, is an impossible task.

For Florida, a vote by mail revote is the best of the worst options available to the state. The way out of the morass for Michigan is less clear, but they will probably have to allow the party to conduct a caucus.