Will Deism ever make a major comeback (in the US)?

[True Federalist (진정한 연방 주의자)]

The idea that Deism was ever mainstream is a stretch, tho it was a major current among those who gave serious thought about religion in the late 18th century. The tendencies towards Deism have more outlets today now that information about Eastern religion and philosophy are generally available, so I doubt that Western Deism will ever have a resurgence since similar Eastern traditions have more depth and breadth of thought.

[True Federalist (진정한 연방 주의자)]

Mikado is correct.

The idea that Deism was ever mainstream is a stretch

It was certainly mainstream amongst a certain social class, and often did not actually involve rejecting Christianity in any serious sense (quite a few Anglican clergy of the 18th century could be described in those terms).

All philosophy was confined to the elite at that time, though.  I don't believe Colonial America even had majority literacy although it was probably above the European average.

Depends on which group of people you consider. For white males literacy ran from a bare majority in the Southern colonies to basically everyone who could learn to read doing so in New England. Females less so, but still a substantial majority in New England.