Lawmakers know the rollout of an immigration bill can be nearly as important as the substance and are trying to draw lessons from the failed push to overhaul the immigration system in 2006 and 2007.

One major takeaway, according to one veteran of that era, is that once a bill is introduced, it has to move quickly, because delay will allow critics to chip away at the proposal and unnerve the fragile coalition holding it together in Congress.

“The longer there is between the time you unveil the proposal and the time you vote on the proposal, the greater the likelihood that it will wind up not making it all the way through to passage,” said a former senior Bush administration official deeply involved in that effort. “Once you’ve got this thing baked, you’ve got to get it out of the oven and into the refrigerator and start eating it pretty quickly. Because if you let it sit on the table — I’m going to beat the metaphor to death — the ants will start eating the cake up.”