It used to be the political assumption that if Ryan brought a bill to the floor that did not have the support of the Republican majority, he risked an internal uprising that threatened his speakership. But now, there's a corollary to the Hastert Rule, named after disgraced former House speaker J. Dennis Hastert.
It's the Trump Rule.
Even on the divisive issue of immigration, Ryan is guided by whether President Trump supports legislation, and that will be enough for him to bring it to the House floor.
"We will not be advancing legislation that does not have the support of President Trump, because we're going to work with the president on how to do this legislation," Ryan told reporters in September, predicting that any bill that has Trump's backing is likely to gain wide support among House Republicans.
Leadership aides point to those comments when pressed about Democratic predictions that any bipartisan Senate deal on immigration will not get consideration in the House because it will fail the Hastert Rule.
The focus now is an audience of one.
Any bill to provide permanent legal status to hundreds of thousands of "dreamers," undocumented immigrants who were brought into the country as children, must get the president's signature. But also critically important is Trump's position as the most vocal proponent of tougher immigration laws and tighter border security.
"If that bill comes out of the Senate and the president says, 'I will sign it,' I think it makes a lot of those issues go away," said Sen. Roy Blunt (R-Mo.), who served in the House-whip operation last decade, when the Hastert Rule took root.
Rather than the old threats of deposing Ryan, or his predecessor John A. Boehner, the most conservative faction of House Republicans would be hard-pressed to complain if the speaker put legislation on the floor that had Trump's blessing — and, with his backing, there is a good chance that Trump would bring on board a majority of House Republicans. "I think you've got plenty of explanation at home as to why the guy who's been the strongest on the border issues believes this is an acceptable solution," Blunt predicted.
Some Democrats see a distinction with little difference. They think there are many bipartisan votes for legislation that would give dreamers permanent status without catering to Trump's demands for border security, but Ryan will not allow the vote.
"In a certain way, that's just a mechanical description of the Hastert Rule," said Sen. Brian Schatz (D-Hawaii), who spent the past week urging his social media followers to study up on the old House principle. "Regardless of whether it's the Trump Rule or the Hastert Rule, when you have major legislation that has 80 percent support among the public, and they're not bringing it to the floor because they're afraid it would succeed, that is a foundational problem for democracy."
Hastert became speaker in January 1999 after the tumultuous rule of Newt Gingrich and just after the impeachment of President Bill Clinton. As he tried to build unity within his fractured caucus, he promised that he would not advance legislation unless the majority of House Republicans supported it.
Democrats cried foul for years, and after Boehner (R-Ohio) became House speaker in 2011, conservative critics railed every time he allowed a bill to pass when a majority of Republicans voted no, eventually driving him out of office in 2015.
The day before Boehner passed the gavel to Ryan, Hastert pleaded guilty to breaking tax laws in paying hush money to a man who accused Hastert of molesting him when Hastert was a high school wrestling coach in the 1970s — a fact that made the "Hastert Rule" even more pejorative in some corners.
As he pulled together the votes to succeed Boehner, Ryan made a pledge to House conservatives that he would not bring immigration legislation to the floor unless it had majority support among Republicans.
Once Trump won the White House, however, that pledge slowly disappeared. It became all about the president and whatever he would support. The belief was that the president's backing would be decisive in getting the requisite support in the House.
"If we have legislation coming through here that is worked with and supported by the president," Ryan said in September, "I'm very confident that our members will support that."
All of this makes Trump's support more critical for any solution to the Deferred Action for Childhood Arrivals program, under which 690,000 dreamers face the loss of their protections from deportation after Trump terminated the program last fall. Republican leaders had grown somewhat frustrated by Trump's shifting positions on the issue, highlighted by a declaration by Senate Majority Leader Mitch McConnell (R-Ky.) that he would begin to move legislation "as soon as we figure out what he is for."
Trump's advisers signaled his positions on dreamers and border security in a carefully scripted conference call with congressional aides Thursday, formally embracing a path to citizenship for up to 1.8 million young undocumented immigrants and $25 billion for the construction of a border wall and increased border security.
There was enough in the initial proposal for conservatives to decry it as "amnesty" and liberals to complain that it contained new anti-immigrant proposals.
But it was a detailed start, and it established a marker for negotiations among a bipartisan group of senators trying to find a compromise.
Blunt remains optimistic that the Senate can thread the needle and that a majority from both caucuses will support a DACA-border bill, leaving the far left and far right disappointed.
"So if you really want to pass a bill, it needs to probably get about 65 [Senate] votes and those need to be pretty evenly divided between the two parties," he said.
In that scenario, the pressure would shift to Ryan and the House — but only if the legislation still has the support of Trump, and only if the president has not changed his position on some key issues. For instance, Sen. Jeff Flake (R-Ariz.), a fierce critic of Trump on many issues, praised the president's call to embrace a path of 10 to 12 years for citizenship for the dreamers.
"If he sticks with this position, I think it's more reflective of where the Senate is," he said.