After taking a back seat for several months to two powerful committee chairmen, Senate Majority Leader Harry Reid (D-Nev.) emerged as the central player in President Barack Obama’s push to enact health care reform this year.

Reid put himself in charge of cobbling together the final Senate bill. He — along with the White House — directed the merger of legislation approved by the Finance and Health, Education, Labor and Pensions committees and called the shots on the controversial public insurance option. (It was Reid who decided to propose a public option with an opt-out provision for the states.)

As the Finance and HELP panels worked on separate health care reform measures, Reid quietly went about soothing the nerves and managing expectations in his Conference. During a tense summer of rising anxiety over the pace of the legislative process and the political aftershocks of passing — or not passing — a bill, Reid massaged egos and worked with liberal and conservative Members of his 60-seat majority to maintain unity and keep Senators focused on the endgame.

Now, with the Senate ready to debate a reform package, Reid will continue to be at the center of the action. He will need to corral 60 votes at nearly every turn, including to get a bill approved — preferably before the chamber adjourns for Christmas. Moderate Democrats are concerned about the public insurance option Reid chose, liberal Democrats are concerned about affordability measures and Democrats, in general, are divided over restrictions for federal funding of abortion. Given the near-unanimous opposition to the bill expected from the Republicans, it is up to Reid to thread a policy and political needle that can stitch these disparate groups together.