What Glenn Greenwald said:

When Obama does things that warrant praise — when he appoints someone like Dawn Johnsen as OLC Chief, or defies Beltway demands by going outside of the intelligence community to find his CIA Director — he should be praised.  When he does things that warrant criticism — such as going on national television to talk about the need for a special process to allow the use of “tainted” evidence against Guantanamo detainees, or when he openly contemplates naming someone as CIA Director who supports rendition and torture, or when he votes in favor of warrantless eavesdropping and telecom amnesty — he should be vigorously criticized.  When he makes statements without any apparent basis — such as Sunday’s assertion that Iran is pursuing nuclear weapons — he ought to be made to account for that claim and show evidence for it.  That’s just basic accountability for a political official.

Like all politicians, Obama is not intrinsically good.  Good things don’t happen by virtue of the mere existence of his presidency.  His presidency will be good only and exactly to the extent that he does good things.  Pressure and criticisms make his doing those good things more likely (there is a quote from FDR, which I cannot find but am certain commenters will quickly cite, where FDR privately instructed his supporters to publicly criticize him for not doing X so that he would be able to do X more easily).

Obama is about to become one of the world’s most powerful political leaders, if not the single most powerful.  He begins with sky-high approval ratings, his political party in control of Congress by a large margin, and enjoys reverence so intense from certain quarters that such a loyal following hasn’t been seen since the imperial glow around George Bush circa 2002.  He’s not going to crumble or melt away like the Wicked Witch if he’s pressured or criticized.  The far more substantial danger is that he won’t be pressured or criticized enough by those who are eager to see meaningful changes in Washington, and then — either by desire or necessity — those are the voices he will ignore most easily.

This is something that I think is universally true – politicians respond to pressure. Confrontational politics work, even when — especially when — they are focused on our friends and allies.