AP Photo/J. Scott Applewhite AP Photo/J. Scott Applewhite

The chatter about the idea of using a “discharge petition” to try to force a House vote on immigration reform has increased, ever since John Boehner suggested reform would be “difficult” this year, and ever since Chuck Schumer endorsed the idea earlier this week.

The immediate rejoinder is: But a discharge petition is hopeless; Republicans will never sign it. That may be. But after talking to folks involved in the strategy, it’s clear this misses the point.

Those mulling the idea don’t expect Republicans to sign it (you’d need around two dozen or more to get 218 signatures and force a vote). Their goal is to give GOP-aligned pro-immigration groups a new mechanism to induce gettable House Republicans to prod House GOP leaders internally to move forward in some fashion.

Here’s the play. There are probably several dozen or more House Republicans that fall into one or more of the following categories: They represent moderate districts and/or are vulnerable to a challenger. They represent local chambers of commerce or agricultural or tech interests who want reform. They are favorably disposed to reform for religious or conservative reasons (yes, there are a few). They represent districts with high concentrations of Latinos. If Dems move forward with a petition, GOP-aligned constituencies — agricultural and tech groups; local and national business groups; evangelicals; members of the GOP consultant class who understand that waiting is enormously risky — would have a new pressure point to use on these Republicans.

The discharge petition allows these groups to say: Here’s your chance; are you with us or against us? Signing a discharge petition is a betrayal of leadership so few if any would sign. But those feeling more heat from these groups pressuring them to sign might now have more incentive to go to the GOP leadership and say they’re getting killed and want the GOP to move forward somehow, even with its piecemeal proposals.

If that happened, that alone could get things moving. But there’s a better case scenario, too, albeit a far fetched one: A single Republican agrees to be the primary mover of the petition. Political scientist Molly Jackman tells me that there’s precedent for this: in two previous instances, members of the majority party sponsored petitions, leading to success, because that gave them “the credibility they needed to actually force a vote.”

The first scenario is the more likely one, and even that’s a long shot. But once you realize getting a petition signed is not the only purpose of this strategy, then you see it might be worth trying.

This also opens up another thing to keep an eye on. The press has widely discussed plans by lefty pro-immigration groups to turn up the heat on Republicans in the wake of Boehner’s announcement. But the real action that matters will have to come from the center-right groups: the U.S. Chamber of Commerce; growers associations and tech interests out west; evangelicals. Will they step up and make it clear to those gettable Republicans that their support this fall is contingent on whether they make a serious effort to pressure the GOP leadership to act? That’s the next thing to watch.