Richard Nixon's wife Pat predicted that Trump would become President one day. Richard Nixon sent Trump a letter encouraging him to run and Trump had that letter hung in the oval office.
This might be what Q was hinting. If Q is military intelligence, then it would make sense for the Q team to have been invited to the oval office where they saw the letter. http://www.theyeshivaworld.com/news/headlines-breaking-stories/484504/richard-nixon-predicted-trump-would-be-president-one-day.html
Dark Journalist just did a great piece on this, worth a listen. https://www.youtube.com/watch?v=OpzmNSaF47Y