This will add half a million contributors to the social security coffers, and half a million taxpayers.
Considering that they had health coverage, but many didn't sign up for fear of being tracked, and were usually restricted to emergency care, they were a burden to the system. this will also lower pressure on ER services.
It's good on many fronts, but it will create a calling effect for undocumented immigration. I'm definitely not on the right's side, but they do have a point.
It's complicated.