The Snowden revelations make clear that U.S. citizens are not protected against surveillance by their own government. Just because foreigners are less protected doesn't change that.
Frankly, U.S. Congressmen don't care what Americans think about U.S. surveillance policy.
They clearly do, because they spend quite a bit of effort trying to shape what Americans think about it, which is inconsistent with not caring what Americans think.
Having a desire for somone to think a particular thing about a subject is exactly caring what they actually think about a subject.
I think the distinction you want to draw is more between being influenced by what Americans actually think, on the one hand, and attempting to influence what Americans actually think, on the other.
But then, again, the only rational reason for members of Congress to try to influence what Americans think is because they think that what Americans actually think impacts the prospects for their political agenda, e.g., by influencing their likelihood of getting elected or influencing the behavior of other members of Congress or the President (perhaps by influencing those actors electoral prospects), so, really, I think that even that distinction is somewhat false. The reason politicians want to shape opinions is because politicians actions do respond to opinions.
The tech industry has more money now than anybody else outside of finance, including the oil industry. It's that simple. Use it.
Congress might care when US corporations' bottom lines are affected by the surveillance. In fact, it's starting to be reported that US corporations are being affected already.
EDIT: To be clear, when US corporations bottom lines in sales to entities in foreign countries. IBM and Cisco have already attributed slumps in sales to foreign entities due to NSA surveillance.