Republicans spent the weekend trumpeting shock and outrage over President Barack Obama’s leaked “backup plan” on immigration. In dysfunctional Washington, this means that prospects for comprehensive reform — including what amounts to an amnesty for the undocumented — are getting brighter.

“Dead on arrival” was the verdict from Sen. Marco Rubio, R-Fla., who has taken on the thankless task of leading his party back within shouting distance of reasonable on the immigration issue. The president’s plan, obtained by USA Today, would leave the nation with “unsecured borders and a broken legal immigration system for years to come,” Rubio charged.

Sen. Rand Paul, R-Ky., said the White House proposal — which hasn’t actually been proposed — shows that Obama is “really not serious” about reform. Rep. Paul Ryan, R-Wis., said Obama’s plan “tells us that he’s looking for a partisan advantage and not a bipartisan solution.”

Translation: Things are looking up!

Here’s the state of play: In the November election, Obama carried both the nation’s largest minority — Hispanics — and its fastest-growing minority — Asian-Americans — by nearly 3-to-1. Rubio, the son of Cuban immigrants, has been trying to explain to his party that immigration is a “threshold” issue for communities with fresh memories of arrival. Mitt Romney’s notion of reform, which he summed up as “self-deportation,” communicated hostility rather than empathy. Voters returned the favor.

So a bipartisan group of eight senators, led by Rubio, has been working to develop a comprehensive reform package that would provide some kind of legal status for the 11 million migrants who are here without papers.

The outlines of a solution are obvious. There would be a clear path to citizenship for those who were brought here as children. There would be provisional legal status, and a route to permanent legal status, for those who came as adults. There would be measures to tighten security along the border with Mexico. There would probably be some kind of guest-worker program for those who seek only to come for seasonal employment. And there would be changes to streamline the legal immigration system, especially for high-tech workers and potential entrepreneurs.

The problem is that Republicans have spent years demonizing undocumented immigrants as a way of appealing to xenophobic, jingoistic sentiment. So how can members of Congress switch from “these people are a plague” to “these people are welcome to stay” without facing the ire of the party’s activist base?

Enter the president’s draft proposal, which administration officials described as a “backup” plan that Obama may put forward if Congress is not able to reach agreement.

It’s really not much different from what Rubio’s group is talking about. But Republicans can slam Obama’s plan as some sort of Kenyan-socialist-inspired abdication of sovereignty. They can blast the provisions on border security as laughable. They can describe the absence of a real plan for reforming the legal immigration process as slapdash, or unserious, or whatever they want to call it.

Republicans in the Senate can line up instead behind a bill that Rubio’s Group of Eight eventually produces; even Paul, a tea party favorite, has indicated he could vote for reform as long as he had more than “a promise from President Obama” on border security. And if enough contrast can be drawn between a Senate proposal and Obama’s plan, perhaps even a significant number of House Republicans can be brought along — if not a majority, then enough to convince Speaker John Boehner to allow an up-or-down vote.

In other words, this isn’t so much about what is being proposed. The bigger factor is who’s proposing it — as former House Speaker Newt Gingrich acknowledged Sunday on ABC’s “This Week.”

“An Obama plan, led and driven by Obama in this atmosphere, with the level of hostility toward the president and the way he goads the hostility, I think it is very hard to imagine that bill, that his bill is going to pass the House,” Gingrich said. But he added that a bill originating in the Senate “could actually get to the president’s desk.”

I believe Gingrich is right. Republican members of Congress have shown a willingness, even an eagerness, to vote against measures that they themselves have sponsored in the past — if Obama is now proposing them.

So if the president really wants immigration reform to pass, one of the most helpful things he could do is put out his own plan as a decoy, to draw Republican fire, while the Senate works toward bipartisan consensus. Which looks suspiciously like what just happened.