What Trump is offering the Democrats is a path to citizenship for the Dreamers. He’d also grandfather in the 4 million people in the backlog of the chain-migration queue. In total, that comes to about 6 million people. He’d also hire more immigration judges and lawyers to eliminate the backlog quickly.
What Trump is offering the restrictionists is a trim in the number of immigrants over time. If new immigrants can only bring in spouses and minor children, and not parents and siblings, the number of people admitted each year under family-based preferences will fall from the present 600,000 a year to something closer to 200,000. And that begins to kick in immediately. If the restrictionist doesn’t like this, he’d find the status quo even worse.
What Trump is offering the fans of the Canadian merit system is a drastic shift from family preferences to economic criteria, which will give us more immigrants that benefit Americans. We would also end the idiotic lottery system. All in all, this won’t admit as many people as a pure merit system would, but, to coin a phrase, half a loaf is better than none.