Immigration advocates I spoke to just now are very pleased with the speech Obama just delivered, in which he offered his principles for reform. They believe he laid out a template for the rest of this battle — one that will make passage of reform more likely. Here’s why:

1) Obama went as far as he could in laying down a firm marker, without trampling on Congress. Obama said: “For comprehensive immigration reform to work, it must be clear from the outset that there is a pathway to citizenship.” The key words there are “at the outset.” The White House set of principles differ from the Senate plan in that the former does not have enforcement “triggers” to set in motion the path to citizenship. With that “from the outset” line, Obama was telling Congress that the enforcement trigger can’t be unreasonable or deliberately obstructive of progress — and the timeline for the path to citizenship can’t be too protracted — to place the path to citizenship functionally out of sight.

Obama also threatened to send up his own bill if the Senate doesn’t act quickly, letting Congress know that they are operating on a tight time frame. “He’s putting pressure on the bipartisan group of Senators, telling them we’re not going to accept any version of reform they come up with,” Frank Sharry of America’s Voice tells me. “He put down a marker to get a path to citizenship that is direct and straightforward, certain and reasonable.”

At the same time, he’s giving Congress the space to work out the details — within those parameters. Of course, what remains to be seen is whether Republicans will be able to accept a “direct, straightforward, certain and reasonable ” path to citizenship, so Obama’s marker is also a straightforward challenge to them.

2) Obama reclaimed the need for immigration reform as the next logical step in the American story. He recast the debate over immigration as one over American values, history, and identity. For immigration advocates, the most important part of the speech may have been this one:

Who gets the privilege of becoming a citizen of the United States of America: That’s a big deal. When we talk about that in the abstract, it is easy sometimes for the discussion to take on a feeling of “us” versusthem.” And when that happens, a lot of folks forget that most of “us” used to be “them.” […] All those folks, before they were “us,” they were “them.”

Obama rebutted the right’s arguments about immigration on two levels. Conservatives argue that giving the 11 million “amnesty” is a reward for illegal behavior. Obama acknowledged that they “broke the rules” and “crossed the border illegally.” But with the above lines, he also recast the granting of citizenship not as a handout to undeserving lawbreakers, but as something squarely in the American tradition, one that has made the country better and stronger.

Obama also talked about previous waves of immigrants who “built this country hand by hand, brick by brick.” Some conservative Republicans have suggested that immigration reform is about creating new ranks of captive, government-dependent Democratic voters. Obama’s allusion to the role of immigrant labor in building the country is an implicit rebuke of this toxic version of the “handout” argument. Says Marshall Fitz, the director of immigration policy for the Center for American Progress: “He had the perfect values frame for this speech.”

By claiming that yesterday’s “them” is today’s “us,” and claiming that we must accept that today’s “them” are becoming “us,” Obama is claiming a mandate for immigration reform from the last election. But not in the way you might think. It isn’t just that the American people support the immigration reforms currently being discussed — polls suggest they do. Rather, it’s that the last election was a bet on the true nature of the emerging demographic makeup of America — on the true nature of the real America — one that Republicans lost and Obama won.

“Many new voters making up the Obama coalition have been demonized as them,” Sharry says. “Obama gave the debate a context that drew on the tradition of e pluribus unum, but connected it to the reality of the demographic transformation of America.”