Democrats who are trying to get an initiative raising the minimum wage on the ballot in Arkansas tell me they have now collected more than the requisite number of signatures — which, if certified, could boost turnout for Dem Senator Mark Pryor, possibly helping determine control of the Senate in this fall’s elections.

Of course, some Republicans still appear to be certain Obummercare alone will deliver Senate control. Karl Rove’s American Crossroads is dumping half a million dollars into a new ad hitting Pryor for “the deciding vote for Obamacare.”

But the law has faded from the headlines — multiple Republicans are running from repeal, Pryor’s GOP foe Tom Cotton included — so maybe, just maybe, other issues could also end up mattering.

A minimum wage ballot initiative could give Pryor a turnout boost among core voter groups who tend to drop off in midterms, and any single race could sway the battle for the Senate.

Dems organizing the initiative tell me they have now amassed at least 10,000 more signatures than the approximately 62,000 required — which, if true, suggests they have a shot at getting them certified, though this is far from a done deal.

“We’re in the 72,000 range, and we still have some volunteer efforts going on in the state, so we’re going to add more on top of that,” Robert McLarty, petition director for the Arkansas Interfaith Alliance, a lead group organizing the effort, tells me. “There could be a challenge from somebody, but we are confident we will get this on the ballot.”

The head of Give Arkansas a Raise Now, another group involved in the push, confirmed similar numbers to the Arkansas Democrat-Gazette (sub. only) and said the signatures would be submitted to the secretary of state later this month.

Pryor has already signaled he will campaign on the issue — the initiative would hike the minimum wage from $6.25 to $8.50 by 2017 –and his campaign tells me he’ll emphasize it to sharpen the contrast with GOP Rep. Tom Cotton, his opponent.

“Mark was the first statewide official to endorse this effort, and he’ll continue to support it,” Pryor deputy campaign manager Erik Dorey tells me. “Mark sees how important this is for working families in Arkansas, unlike our opponent, who has been silent on this issue. This is an important contrast with our opponent.” Cotton has said he supports this going to the voters but hasn’t taken a position.

Presuming this does get on the ballot, Dems hope it will give core voters a reason to vote amid a bad national environment. Jennifer Duffy, who tracks Senate races for the Cook Political Report, says that’s a reasonable possibility.

“It’s important,” Duffy says. “One way Democrats hope to get their base out is by putting ballot initiatives in states with tough races, to give people a reason to vote.” Duffy added the minimum wage on the ballot could boost turnout among working class women and African Americans.

Dem strategists are looking at the minimum wage as a way to draw out members of the Rising American Electorate (unmarried and downscale women, minorities, young voters) in multiple races, by giving them something to vote for. As Celinda Lake puts it:  “This is a great way to frame a race. It gives voters a way to say, `just tell me whether you’re for or against this.’”

A ballot initiative could clarify the choice even further. While all kinds of factors will determine Senate control — and while a 50-50 Senate battle could end up swinging heavily to one side or the other — it’s also possible control could be decided on the margins.

“In a state that is so red where you need every single vote you can get, putting something on the ballot that appeals to your base is one more weapon in the arsenal,” Duffy says. “We’re looking at a number of races that are going to be very, very close to the end, and any of them can make or break the majority. Getting a few thousand drop-off voters out in some cases could decide the outcome.”

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.