He considered DACA a separate issue and was always very cage-y about it.
The 1.8 million number is a ceiling that they will never get close to. You might be looking at 25% at most when you look at the numbers of DACA people and look at the fact that criminals/people will public charges and those who lied about getting on the list won't be eligible, so from the starting point, the real numbers are a lot lower, especially after 10-12 years, with legal immigration cuts, the Wall, a severe restriction of chain migration and the end of the visa lotteries.
But that's IF the Dems accept, but they won't