House Democratic leaders will announce at a presser tomorrow that they will file a discharge petition to try to force a House vote on the minimum wage hike, a Dem leadership aide tells me.

AP Photo/Pablo Martinez Monsivais AP Photo/Pablo Martinez Monsivais

The move was expected, but it’s good to have confirmation that it will happen. House Dem leaders have already confirmed they don’t expect House Republicans to sign it — it would require as many as two dozen GOP signatures to get the 218 it needs to force a vote. But they still think the move is worthwhile, because it could help sharpen the contrast between the two parties’ economic agendas heading into the 2014 elections.

What’s more, even if House Republicans don’t support a discharge petition, it is possible House Republicans will come under pressure to take up a minimum wage hike anyway. That’s because the possibility of it passing the Senate can’t be ruled out entirely. Indeed, Bloomberg reports that GOP Senator Susan Collins is looking to round up some Republican Senators in support of a hike:

Another consequence of the holdup is that it gives more time to Senator Susan Collins, a Maine Republican, who said she’s seeking bipartisan support for a less costly measure.

“I haven’t settled on particular numbers,” Collins said in an interview. “I’m just trying to figure out what would do the most, in terms of not creating disincentives for employers to create jobs, and to help some of the low-income families.”

Meanwhile, there’s been some chatter to the effect that red state Dems might get squeamish about a minimum wage vote, but Senator Joe Manchin of West Virginia today said he’s on board.

There’s obviously good reason to be skeptical that GOP Senators will support any minimum wage hike in the end. A handful initially supported the unemployment benefits extension, only to come out against it in the end, citing fiscal concerns. But GOP Senators that are up for reelection in 2016 in blue or purple states — like Ohio’s Rob Portman and Illinois’ Mark Kirk — continue to sweat the pressure on them over UI, because they will be facing a very different electorate in 2016 than the one that lifted them into office in 2010.

The 2016 electorate — thanks to the fact that it will be a presidential year — will be made up of far larger numbers of voters from the Dem Coalition of the Ascendant, so it seems possible that GOP Senators facing that electorate might pause before voting No on the minimum wage hike.

Indeed, the minimum wage issue is already emerging as key to Dem hopes of getting out their core voters this year, and it even flared up as an issue today in the Kentucky Senate race. Dem Alison Lundergan Grimes’ pollster, Mark Mellman, has already said it will be key to getting downscale women to the polls. And in Kentucky today, Bill Clinton talked up the minimum wage hike — which Grimes supports — as good economic policy and a crucial boost in the living standards of working people. Clinton cited it as part of his effort to contrast Grimes’ economic agenda with that of Mitch McConnell, “who’s not for doing anything and just obstructs things.”

Meanwhile, right on cue, McConnell had this to say about whether the minimum wage hike should get a Senate vote: “I would hope not.”