When Sen. Patrick Leahy made the surprise announcement last December that he'd turned down a promotion to chair the Senate Appropriations Committee, his explanation went something like this: With immigration reform and gun legislation on the Judiciary Committee's agenda — not to mention a possible Supreme Court nominee or two — that's where the action would be.

Turns out he was right.

Just minutes before the Senate passed sweeping immigration reform legislation Thursday afternoon by a vote of 68 to 32, Leahy paused to reflect on the role his committee played in the bill's passage.

Over the course of three weeks, he said during a speech on the Senate floor, the Judiciary Committee spent 37 hours debating and amending the bill.

"We considered 212 amendments from Democrats and Republicans and approved 136 amendments in a room filled with spectators on both sides of the issue," Leahy said. "Of the amendments approved in committee, 47 were Republican amendments and all but three were adopted with bipartisan support. Even the staunchest opponents of this legislation have praised the Judiciary Committee's process for consideration of this bill."

Well, if I don't say so myself!

So how integral was Leahy to immigration reform's passage? BuzzFeed, the cat and politics web site, took a stab at answering that question Thursday. 

While Leahy was not a part of the bipartisan eight-member group that drafted the bill, BuzzFeed's Kate Nocera reports, he "might as well be the Gang of Eight's ninth member." Here's more:

As the Judiciary Committee’s chairman and the Senate’s longest-serving member, Leahy — more than most Democrats — has had to carefully negotiate his deep-rooted progressive principles with his desire to get the comprehensive immigration reform bill out of the Senate.

And as the Senate is on track to pass the Gang’s carefully compromised bill Thursday afternoon, members on both sides of the aisle give a huge chunk of the credit to Leahy for helping usher it through.

As Nocera notes, Leahy "hasn't been shy about voicing his criticism since the the Gang of Eight first started meeting to craft the legislation." At first, Leahy seemed put-off that the gang — not his committee — had been tasked with writing the bill's first draft. When the group failed to meet a couple deadlines, Nocera writes, "he told them to hurry up."

In the end, Leahy worked closely with the gang to keep opponents from blowing up the bill with unfriendly amendments in committee and on the floor, where he was charged with managing debate. 

One secret weapon Leahy had at his disposal?

As the New York Times reported last week, the Obama administration set up a "war room" of sorts just down the hall from the Senate Judiciary Committee, "to quietly secure passage of the first immigration overhaul in a quarter century."

Leading the administration's team was Ed Pagano, the former UVM basketball center who joined Leahy's staff in 1993 and became the Vermont senator's chief of staff in 2005. In January 2012, Pagano was tapped to become the White House's chief liaison to the Senate.

The Times' Michael Shear describes one recent day in the immigration reform war room like this:

At one point, Mr. Pagano, Ms. Escobar and the other White House advisers huddled for 45 minutes in the smaller of the two rooms with Mr. Leahy’s top aides. Working from spreadsheets, they discussed each of the 10 amendments that Mr. Leahy was likely to bring to the floor for a vote that day.

“When Republican amendments are filed and we are trying to decide, ‘Can we accept this? Can we accept this without some modifications?’ they are the ones who tell us, ‘This is quite doable,’ ” said one Democratic Senate leadership aide, who requested anonymity to talk about legislative strategy.

So, again, how integral was Leahy to the bill's passage? Well, he's holding a press conference at 11 a.m. Friday at his Montpelier office — and we expect he'll have an answer to that question then.