It’s election day, already, come Saturday. And that’s before the major candidates have really started selling voters on their virtues and their opponent’s faults.

Early voting begins Saturday and continues for a week, except Sunday. It is a significant component of the final turnout of voters for the Nov. 21 runoff for governor. An interesting challenge is thus prepared for John Bel Edwards and David Vitter soon after the primary.

The turnout of 1.1 million voters in last month’s primary did not reach 40 percent and experts say that gross numbers of ballots cast are in a long-term decline — down by some 500,000 since 1983, as Robert Travis Scott of the Public Affairs Research Council comments today. Of course, that was when another Edwards — Edwin, no relation to John Bel — had vast amounts of money to spend on a tried-and-true Democratic turnout machine.

That Democratic machine no longer exists. Lower turnout overall makes the citizen who shows up a precious resource for the campaigns.

The rule of thumb is that lower turnout helps Republicans. Another rule of thumb is that local races help turnout; that is good news for Vitter in that the few runoffs of consequence around the state tend to be in GOP-leaning parishes. There’s a parish president’s runoff in Ascension and a sheriff’s runoff in Lafayette.

But in a race in which the adherents of the two GOP finishers out of the money — Scott Angelle and Jay Dardenne — are bitter about Vitter’s attacks on their integrity, there are a lot of middle-of-the-road GOP voters who are up for grabs.

The Edwards of today is leading in polls and likely will have adequate money for turnout activities. At one time, the conventional wisdom would be that Edwards would be the runoff underdog in a Republican-leaning state, but this has been the Halloween of Vitter’s discontent, and the U.S. senator’s campaign is sputtering.

The map of runoffs does not favor Edwards. There are a few runoffs for legislative seats or local races in Orleans and East Baton Rouge, where Edwards could be expected to do well.

However, two seats on the Board of Elementary and Secondary Education are in runoffs, in the Shreveport and Baton Rouge areas. Teacher unions, closely allied with Edwards, are likely to push turnout for those formerly obscure bodies, which should help the Democrat at the top of the ticket.

The good news for Vitter is that the GOP is better organized for phone banks and the other grass-roots turnout activities than the Democrats. Can Edwards compete in organization? Today’s Democratic effort will be a far cry from the days of just writing checks to yesteryear’s political machines of COUP, BOLD, SOUL — the famous acronyms that made Orleans Parish “an ATM for Democrats,” in the words of the late John Maginnis. The sheriffs’ endorsement of Edwards may help with turnout for him around the state.

A key factor in turnout is not mechanical but motivational. Here, early voting helps Edwards.

Vitter’s negative campaign ads seeking to tie the social conservative Edwards to President Barack Obama may be galvanizing to the GOP base, but Vitter’s party affiliation ties him to the unpopular Gov. Bobby Jindal.

If voters today know anything about Edwards, it’s that he’s been against Jindal in the Legislature, and that he is a West Point graduate who served in the 82nd Airborne. Those who vote early, if polling is an indicator, probably have a much more positive view of Edwards than of Vitter.

Lanny Keller is an editorial writer for The Advocate. His email address is lkeller@theadvocate.com.