Shadi Hamid makes an obvious yet weirdly neglected point about Democratic efforts to look "tough":
The problem is that many Democrats fall into the trap of “overcompensation,” that, fearful of being painted as soft on security, we take public positions that appear contrived, because they are in fact contrived, a function of our obsession with polls and focus groups more than a function of deeply-held liberal values. [emphasis added]
This is not to be naïve and just say that any genuine position of conviction is going to be sellable. Nevertheless adopting positions that are obviously motivated by narrow political considerations doesn't do much to improve things. "Appearing to be principled" is an important part of politics as well. What's more, it's helpful to at least understand principles so that when you need to talk about Topic X in July you don't wind up saying things that will be inconsistent with what you say when Topic Topic Y suddently becomes hot in September.