"For seven years, Republicans insisted that every security procedure ever conceived was absolutely essential to keeping the American public safe, and anyone who disagreed was practically rooting for an al-Qaeda victory. Now a Democrat is in office and suddenly they're outraged over some new scanners. Helluva coincidence, no? But this is no surprise: this issue works for them on every possible level. In the short term, it gives them something to pound Obama about. In the medium term, it gets the chattering classes chattering about something other than the fact that Republicans have no remotely plausible plan for improving the economy. And in the long term, if a plane does come down, they will absolutely crucify the Obama administration for its abysmal and cavalier approach to national security."
I think there's some truth to what Drum says toward the end of this paragraph. One reason the Obama Administration isn't backing down on this issue, I suppose, is that the political fallout will probably be ferocious if they do and then there's a successful attack.
However: I don't ever want to be in the position of dismissing a civil liberties issue because it otherwise gives undue advantage to one's political rivals. That way lies hackery. Are Republicans making hay out of the TSA backlash? Sure. Do I care? Not so much. Maybe they're doing it cynically, but in this case at least they're on the side of angels. It's the principle that matters, not the party.