That’s true, it won’t be all; just between 60 and 75%.
There is very little chance we’d ever do better than that so long as mass immigration continues. The only way we’ll ever avoid a total rout with them is if mass immigration comes to an end (legal and illegal) and assimilation has time to work.
If the border is secure and new technology like DRONES are used (yes Rand doesn’t mind using drones for proper things like surveillance just not killing them!) then hopefully the tide can be stemmed of illegal crossings. Legal immigration and giving more visas out can only happen if there’s jobs for them and businesses need the immigrant. If the immigrant is working and not claiming welfare then he has a good work ethic and I would argue when/if he becomes a citizen is more likely to be a GOP voter after he sees how the Democrat policies work out.