Democrats want to allow four categories of people in the U.S. legally to apply for permanent residence: DACA beneficiaries, Temporary Protected Status recipients, farm workers and essential workers.

Last Friday, Democrats presented their case to the parliamentarian behind closed doors for why this policy complies. It is unclear when the ruling will come but Democrats are bracing for it as early as this week.

They argue it would have a direct and substantial impact on revenue through the fees for the costly the application process and the taxes the immigrants would pay, which proponents say could generate more than $100 billion in the long term. They cite precedent on making immigration changes in budget reconciliation, including one from 2005 on recapturing unused green cards.

Democratic staffers came away optimistic that they made a strong case, according to sources familiar with the meeting. But Durbin, an Illinois Democrat and chairman of the Judiciary Committee, has seen near-misses on immigration before.