Marketplaces of Ideas v. Command Economies of Ideas

From The Observer:

The demented, bullying tone of the websites is another symptom of the descent of public discourse in America and, frankly, one can easily see the attractions of self-censorship on the question of Middle East and Israel. Read David Horovitz for longer than five minutes and you begin to hear Senator Joseph McCarthy accusing someone of un-American activities.

[...] The bottom line,' say Mearsheimer and Walt, 'is that AIPAC is a de facto agent for a foreign government, has a stranglehold on Congress, with the result that US policy is not debated there, even though the policy has important consequences for the entire world.'

[...] That is my belief, but these things are rarely discussed in America. People look vaguely queasy when you raise the subject of the Israeli lobby, as though the only concern in American discourse is not to appear anti-semitic, a fear which, I suggest, is sometimes shamelessly played upon.