Absentee ballots have been flying out of county elections offices throughout Minnesota in the past month, Secretary of State Mark Ritchie reports. Requests for the mail-in ballots have been running nearly double those made in the last presidential election, in 2004.

We cheer that word as a harbinger of a high-turnout election Tuesday. This year's history-making campaign deserves to end with a blow-out turnout, of the sort that will give the new president and Congress legitimacy and assurance that they represent a majority of this nation's citizens. Nationwide, turnout ought to top 60 percent this year, as it did routinely before 1972, but has not since.

This year's high demand for absentee ballots likely also signifies something else. In Minnesota and around the country, voters are demonstrating a desire to exercise their franchise at times and places other than the first Tuesday after the first Monday in November, between the hours of 7 a.m. and 8 p.m., at a polling place near their homes.

Minnesota does not allow early or no-excuse absentee voting. That puts this state in a shrinking minority: 31 of the 50 states offer voters wider opportunity than Minnesota does to cast a ballot before Election Day, according to the National Conference of State Legislatures. Ritchie estimates that a third of the ballots counted in this country on Tuesday night will have been cast today or earlier. In some states, voters began marking their ballots as early as Sept. 23.

Some things of value -- camaraderie, the spectacle of democracy on display, a same-day snapshot of national will -- are lost when voting is spread over time and place. But election officials attest that something more important grows: participation. When states switch to mail and early voting, more people vote.

Minnesota has led the nation in presidential-year voting for years, to a great extent because since 1974, Minnesotans have been able to register to vote at the polls on Election Day. But even here, allowing the smallest rural towns and townships to operate their elections by mail has produced a turnout spike.

State law gives that choice to townships with fewer than 400 registered voters. Patty O'Connor, director of taxpayer services in Blue Earth County, said that in nine Blue Earth townships that have switched to mail voting, turnout in the 2008 primary was more than double that of the comparable 2004 in-person primary. She said people appreciate being able to take their time filling out their ballots, and are pleased to avoid standing in line at the polls.

Results like those have state election officials interested in extending the mail voting option to more places. O'Connor thinks the option should be available statewide. "This is the best way to get people engaged," she said.

Such testimony should count for much with Gov. Tim Pawlenty and the 2009 Legislature. They should take care to maintain one feature of current absentee ballot law: Those who vote early should always be allowed a chance to change their vote on Election Day, by appearing at the polls or a county courthouse. Minnesotans know too well that events in the latter days of a campaign can dramatically alter an election.

With that safeguard, Minnesota ought to broaden the opportunity for people to vote before Election Day. As evidence of early voting's appeal mounts, a state that prides itself on its nation-leading level of participatory democracy can scarcely do otherwise.