I'd say this about Pats fans in high school: often times kids pick teams that are winning (lots of Bulls-Cowboys-Yankees fans in my generation) as their primary team, and then ease into whatever their parents' teams are. My dad was a die-hard Celtics fan, but as an elementary school kid in the early-90s, I identified more as a Bulls fan: Jordan posters in my room, all that jazz. As I began to watch more games with my father--and as the Bulls waned--I slid more comfortably into a Celtics fan. They were always a team I liked (both parents loved them), but most kids are front-runners.
I think in the 90s, in particular, there were a slew of Cowboys fans (not me...first football memory was the Giants-Bills Superbowl) that I'd wager now--as adults--more readily identify as Jets or Pats fans...maybe even Giants.