In most cases (shockingly), it's not really the politicians, or at least not enough of them to make the changes that the FBI, CIA, NSA, et al. are pushing for. For decades now, the law enforcement and intelligence communites, along with a small handful of politicians and judges who refuse to learn anything about technology, science or math, have been pushing for any kind of encryption backdoor they thought they could sell. So far, Congress has consistently refused to grant them the powers they've been asking for, which is really what the 'iPhone of terror' (I'm totally stealing that, BTW) is all about. Now they're trying to get several federal judges (with the one in San Bernardino being the most high profile case) to give them a new power that Congress has repeatedly denied them, based on a ludicrous and unprecedented interpretation of a 200 year old law, telling the judges that it's "just this one phone" and "it won't set a precedent" while simultaneously arguing to Congress that this is going to set the precedent that they need.

One judge already has rejected their claim that the All Writs Act gives the court the power to do what the FBI wants to do, and I doubt Congress is going to cave and give the FBI a power that it's been withholding from it for decades in spite of repeated requests, hearings and arguments on the subject(and even in the wake of 9/11 when the law enforcement and intelligence communities were given all kinds of new surveillance powers).

Also don't forget that while they get away with a lot, American politicians do have their limits before the people start pushing back. They sneak a lot of things past a mostly uninformed public, but the people were able to stop things like SOPA/PIPA (at least at the time.. sadly a lot of that got slipped into TPP while nobody was allowed to look) and even the "Clipper chip" backdoored encryption they were pushing for back in the Clinton days.