[dr_lew]

“Many Americans think the constitutional restrictions on religion in public schools are tighter than they really are,” Pew researchers wrote.

That's because they are tighter than they "really are". That is, they are tighter de facto than they are de jure.

[thulldud]

That's because they are tighter than they "really are". That is, they are tighter de facto than they are de jure.

That's because the teachers and administrators are the ones who think they are "tighter than they really are."