Tensions were raw ahead of midnight as Republican leader Mitch McConnell rose in the Senate for the purpose of publicly ridiculing Majority Leader Chuck Schumer over the daylong delay as Democrats argued among themselves over the $1.9 trillion COVID-19 rescue package. But 12 hours later, it was Schumer, D-N.Y., reveling in the last word, an unabashedly upbeat “help is on the way” to Americans suffering through the pandemic and lockdowns as the Senate prepared to approve the massive package without a single GOP vote. Senate passage of the sweeping relief bill Saturday puts President Joe Biden´s top priority closer to becoming law, poised to unleash billion for vaccines, $1,400 direct payments and other aid, and shows Schumer, in his first big test as majority leader, can unify the ever-so-slim Democratic majority and deliver the votes. “Lessons learned: If we have unity, we can do big things,” Schumer told The Associated Press in an interview after the vote. The outcome “gives us optimism about doing more big things in the future – because it worked,” he said. Stewardship of the massive pandemic relief package was an inaugural foray of the new power dynamics of Washington, testing Democratic control of the White House and Congress for the first time in a decade, and setting the foundation for what´s possible for Biden´s agenda. So much of Biden’s success or failure depends on the Senate, where Democrats are in command of an evenly split chamber, 50-50, a majority so delicate that any one senator can upend the legislative agenda. While Vice President Kamala Harris is able to break tie votes, Schumer has zero slack if Republicans are opposed, voting lockstep as they did Saturday against the virus aid as bloated and unnecessary. One key centrist, Sen. Joe Manchin, D-W.Va., wavered over an unemployment provision, throwing the proceedings into chaos before a grueling all-night session. Biden has been telling senators privately their vote on pandemic aid will build momentum for the next priorities. An ambitious infrastructure package is emerging, part of his “Build Back Better” campaign agenda, to bring roads, broadband and green-energy projects nationwide. He and Schumer spoke often as the Senate leader steered the pandemic aid to approval. It’s now headed back to the House for a final vote, as soon as Monday. While no senators appeared ready to tank Biden´s top priority, the next votes could prove more difficult. “There´s a whole series of issues that that quite a few of us were discussing,” said Sen. Chris Coons, D-Del., a Biden ally eager for bipartisanship, who spoke to the president a few minutes after the vote. “This was a reminder yesterday that, in a 50-50 Senate, if any one member changes their mind on an amendment, or vote or an issue, it can change the outcome,” Coons said. Voting rights, immigration law changes and other bills will be subject to filibuster rules that require 60 votes for passage, rather than 51, a potentially impossible hurdle in the face of Republican opposition that is stoking calls to change the process to ensure Biden´s priorities don´t flame out. “We´re going to have to have discussions about that,” said Sen. Debbie Stabenow, D-Mich., a member of leadership. But that tough topic was for another day. On Saturday, Democrats elbow-bumped and cheered in the chamber – Stabenow said some were almost in tears — as they ushered the massive aid package they had promised voters to approval. With 10 million jobs lost and countless schools and businesses shuttered, it includes $300 a week in extra unemployment benefits, money school reopenings, eviction protections and small business assistance.