It probably wouldn’t be a good idea to expend political capital trying to implement the “muslim ban”, though as others have stated he’d already moved to enhanced vetting and scrutiny to people from particular nations. He should definitely follow through on this promise of extra scrutiny.
A more comprehensive, conservative approach to reforming legal immigration would be preferable to the ‘muslim ban’ anyway, as it could generally end Democrat-importing mass immigration and would largely take care of the problem.
1. Drastically reduce refugee/asylum admittances, of which many go to Muslims. As President, Trump can do this all on his own. Obama has increased the total annual number from 70,000 to over 100,000 per year. Trump could and should slash that number so that it’s much closer to zero. As part of that, he should simply not accept significant numbers from Muslim nations.
2. Work with Congress to abolish the absurd Diversity Lottery Visas. Many of these go to people in Muslim nations, and they in turn kick off chain migration.
3. Work with Congress to end extended family chain migration. Restrict family immigration to spouses and minor children. Without the adult-sibling and adult children categories, the almost never-ending pool of potential future Muslim immigrants will dry up.
Do these things and Muslim immigration would be greatly reduced.
Yes. Absolutely.
It can be done without an overt ban in Muslims.
And that’s how it should be done as soon as possible.
No reason not to now.