The bipartisan Senate "Gang of Eight" held together despite an onslaught of amendments and some efforts to kill its comprehensive immigration reform bill.
Tonight, the Senate Judiciary Committee passed the bill 13-5, largely intact, to the full Senate for a vote.
It is the first step in a series of hurdles for immigration reform that includes increased border security, a pathway to citizenship for 11 million undocumented immigrants and reforms to legal immigration designed to streamline the process.
The committee vote was met with cheers of, "Yes, we can," by those in the room.
It took the 18 senators five days for markups and they considered 300 amendments, with many of those that passed doing so in a bipartisan nature. Overall, 48 Republican amendments passed.
"I don't think there has been a markup on such a complex bill that has been this open," Sen Patrick Leahy, D-Vt., said during closing remarks.
The entire mark-up was streamed live via the committee website, with active tweeting by the senators and their staffs upon passage or failure of an amendment.
"I appreciate the work of the Senate Judiciary Committee in taking the bill my colleagues and I introduced in April as a starting point for debate," said Sen. Marco Rubio, R-Fla., a member of the "Gang of Eight." "We have a historic opportunity to end today's de facto amnesty and modernize our immigration system to meet our 21st century needs. I remain optimistic that the Senate, by improving the bill through an open and deliberative floor debate, will seize this opportunity."
Late in the day, the bill survived perhaps its most serious challenge when the Democratic committee chairman Leahy introduced and then withdrew an amendment that would have granted gay and lesbian couples the same rights as straight married couples to sponsor their foreign-born partners for immigration.
Democrats who supported the notion said they could not vote for the amendment because it would have fractured the fragile, bi-partisan coalition that wrote the delicate legislation.
Republicans said they would walk away if the amendment was included, resulting in Leahy vowing to fight the battle another day.
"So, with a heavy heart, and as a result of my conclusion that Republicans will kill this vital legislation if this anti-discrimination amendment is added, I will withhold calling for a vote on it at this time," he said. "But I will continue to fight for equality."
There were few, if any, significant changes made to the original "Gang of Eight" bill.
One major addition was the biometric entry/exit at the 10 U.S. airports with the highest volume of international air travel within two years of the bill's passage.
A deal struck between Sen. Charles Schumer, D-N.Y., and Sen. Orrin Hatch, R-Utah, today could triple the annual number of temporary visas for workers in highly skilled fields like engineering and technology, and was enough for Hatch to give the full bill his support to leave committee.
It will now head to the full Senate for more debate and a vote.
"Now the real work begins to see if we can reform this bill before we send it to the House," Sen. Chuck Grassley, R-Iowa, said during closing remarks.
The separate House "Gang of Eight" said last week it had agreed in principle on its own bill and expected to write its legislation and introduce it after the Memorial Day recess.
"We can do it," Leahy said during closing remarks. "Now, let's go out of this room and work with other members of the Senate and the other body ... and we will be a better Senate, a better Congress but, most importantly, a better country for it."
Senate Minority Leader Mitch McConnell, R-Ky., indicated he wouldn't stand in the way of the immigration bill coming to the floor of the Senate after getting out of committee.
"With regard to getting started on the bill, it's my intention, if there is a motion to proceed required, to vote for the motion to proceed so we can get on the bill and see if ... we're able to pass a bill that actually moves the ball in the right direction," McConnell said today at the Ohio Clock stakeout. "I think the 'Gang of Eight' has made a substantial contribution to moving the issue forward. So far, I'm told that the Judiciary Committee has not, in any fundamental way, undone the agreements that were reached by the eight senators. And so I'm hopeful that we'll be able to get a bill that we can pass here in the Senate."
Senate Majority Leader Harry Reid, D-Nev., today praised Leahy for doing a "masterful" job of moving through the bill.
President Obama also applauded the movement of the bill to the full Senate and said its principles are "largely consistent with the principles of commonsense reform I have proposed and meets the challenge of fixing our broken immigration system."
"None of the committee members got everything they wanted, and neither did I , but in the end, we all owe it to the American people to get the best possible result over the finish line," Obama said in a written statement. "I encourage the full Senate to bring this bipartisan bill to the floor at the at the earliest possible opportunity and remain hopeful that the amendment process will lead to further improvements."
ABC News' Sunlen Miller contributed to this report.