Why were they wiretapping Trump for years?
Prophecy believers?
They read some of his early books and knew that he was a threat to their precious Swamp and critters like them.
They (NSA where Montgomery worked) is believed to be wiretapping everyone. These were probably just excerpts of Trump they extracted going all the way back to the birth certificate fued that Trump was having with Obama. They probably wanted to know how much information Trump had learned on that, among other things.
My guess (pure speculation) is that it started when Trump publicly questioned President Obama’s birth certificate.
Birth Certificate inquiry.
Probably not just Trump; how else are they going to blackmail billionaires into contributing to the DNC and the Clinton Foundation. Apparently Trump is the only one they had no dirt on, 600 million pages can’t be on just one person.
That’s my conspiracy theory in a nutshell.
Recall that Trump was very vocal about Zero's phony Certificate of Live Birth before the 2012 election. That made him a threat to the regime, and thus a target for surveillance.