It is a cliché, but clichés are rooted in truth, and this is no exception: It will all come down to turnout.

In the last several elections, both in Minnesota and nationally, voter turnout has spiked and collapsed depending on whether it was a presidential race or not. In 2012, for instance, Minnesota led the nation with a 76 percent voter turnout. In 2014, however, just 51 percent voted.

And those numbers figure prominently in determining the winner. Republicans are more reliable voters, while the DFL has trouble motivating its supporters when a presidential standard-bearer is not on the ballot.

So in recent years, the GOP has captured one or both chambers of the Legislature when there’s no presidential race, as in 2010 and 2014, while the DFL ran the table for President Obama’s election in 2012.

Minnesota Republican Party Chairman Keith Downey declined to give specifics about the mechanics of his turnout operation but said the party and its candidates would have a robust campaign for early and absentee voting and a program for mobilizing on Election Day.

Max Rymer, a House challenger in the west-metro suburbs, said he is impressed with the GOP voter data he’s been able to access to make sure he and volunteers are hitting the right houses and making the right pitch.

Downey said the GOP is dealing with a fairly unusual phenomenon on its side: inexperienced voters. “You look at people coming through [the] State Fair booth, and you realize these are not traditional Republicans who are going to participate.”

Republicans have to scoop them up and make sure they vote: “It’s an extra challenge, but you have to make sure you reach them,” Downey said.

Ken Martin, chairman of the DFL Party, knows all about inconsistent voters. They’re a key source of his anxiety every two years.

The DFL has 25 field offices and more than 300 people on staff, most of them collecting data, recruiting volunteers and pestering their voters to come out this year.

This weekend, the DFL is doing a turnout dress rehearsal of sorts they’re calling “Minnesota Knock Together,” expecting 300 to 400 volunteers who will knock on doors across the state.

Part of the reason that turning out your voters has become so important is that fewer voters are open to persuasion. According to Michigan State University political scientist Corwin Smidt, the percentage of voters in presidential campaigns who float from one party to another has declined from a high of 15 percent in the 1960s to just 5 percent today.

Martin said his staff and volunteers can’t just focus on turnout, however. They also have to persuade independents and soft Republicans, especially in weaker DFL districts. “It’s not either/or,” he said of persuasion and turnout. “You do both simultaneously.”

Martin also criticized the GOP operation. “Their turnout infrastructure ... is invisible,” he said. Republicans have two months to prove Martin wrong.

Twitter: @jpcoolican