WASHINGTON — President Obama’s nonconfrontational tone on an immigration overhaul in his State of the Union address on Tuesday night probably did more to advance the issue, lawmakers said, than if had he offered a fierce rallying cry, as he did about gun restrictions.

As senators gathered Wednesday for the first hearing on the proposed sweeping changes in immigration law, they said the president’s decision to give members of both parties room to maneuver on the delicate politics of immigration was a strategic choice that could pay off as negotiations continued.

“He’s walking a tightrope here, trying to allow Congress on a bipartisan basis to come up with a comprehensive immigration reform bill in the Senate,” said Senator Richard J. Durbin of Illinois, the No. 2 Senate Democrat. “He encouraged us, told us he doesn’t want this to drag on forever, and if we can’t get it done he’ll play more forceful role.”

Mr. Durbin, a member of a bipartisan group of eight senators working on an immigration bill, added, “The reason he’s on this tightrope is the Republicans don’t want to make it appear that they are bending to the president on this issue.”