But there’s no doubt among his Senate Democratic colleagues and aides that Schumer wants to succeed Reid. The bipartisan passage of a landmark immigration bill will go a long way in addressing any lingering concerns about his ability to lead the Democratic caucus.

“Everyone knows he is a great political strategist and a great communicator. Now they know he’s a consummate legislator,” said Jim Kessler, who worked for Schumer before becoming the senior vice president for policy at Third Way, a Democratic think tank.

Schumer has had other significant legislative accomplishments in the upper chamber. He helped push $20 billion in funding for the victims of the 9/11 terrorist attacks through a GOP-controlled Senate; he added the college tuition tax credit to the 2009 stimulus package; and he secured funding for the cleanup of Hurricane Sandy last year…

“He’s been often described in the past as a fierce partisan, a very political person by nature, but in this particular instance he has demonstrated real willingness to reach across the aisle and work with Republicans,” said Jim Manley, a former senior Senate Democratic leadership aide. “It’s impressive that Republicans in the Gang of Eight put aside their views of him as hyper-partisan to work on this proposal.”