The real danger is that those who defend Obama the Candidate no matter what he does are likely to defend Obama the President no matter what he does, too. If we learn in 2009 that Obama has invoked his claimed Article II powers to spy on Americans outside of even the new FISA law, are we going to hear from certain factions that he was justified in doing so to protect us; how it's a good, shrewd move to show he's a centrist and keep his approval ratings high so he can do all the Good things he wants to do for us; how it's different when Obama does it because we can trust him? It certainly looks that way. Those who spent the last five years mauling Bush for "shredding the Constitution" and approving of lawbreaking -- only to then praise Obama for supporting a bill that endorses and protects all of that -- are displaying exactly the type of blind reverence that is more dangerous than any one political leader could ever be. Read more.
This whole FISA thing is being framed as moderate vs. insane, strong vs. weak, shrewd vs. politically obtuse, flexible vs. rigid; realistic vs. naively idealistic and from where I stand it's exactly the kind of thinking that gets us into trouble time and time again. This calculation by the Obama camp is led by the kind of thinking that led Clinton and so many other Dems to vote to support the war--but in many ways worse: Lots of things are negotiable in the political arena; constitutional principles are not among them.
There are always good reasons for doing the wrong thing. There would be no such thing as a tough moral or political choice if that were not the case. Obama is doing the wrong thing and any argument to justify it by Obama supporters is either cynical or a naive ex post facto rationalization. I don't expect a pure candidate. I expect a candidate to know where you draw the line, and Obama has raised very serious doubts about whether he knows where that line is.