The most important factor, I think, is the variety of voices in American public life, including a phenomenon that is frequently decried: partisan polarisation and its highbrow cousin, epistemic closure. That is, America has Glenn Beck and Andrew Breitbart and Keith Olbermann and DailyKos. One side pushes; the other pushes back. America can have individuals and institutions with disproportionate influence—the Koch brothers, the teachers’ unions—but none of them command hegemonic support, nor could they, under current conditions. They get influence by ginning up people to care about their cause, not by calling up the president and giving him the what-for. News Corporation might own the company that owns the Wall Street Journal, but when that paper came up with a quasi-defence of News Corporation yesterday, there were plenty of papers ready to push back.
Another factor, I think, is that American electoral cycles bring politicians into regular, recurring contact with the common man (who is actually an older white lady living in Iowa). It is therefore difficult for any particular news outlet to claim to be the voice of the people, as the British tabloids do. See, for example, Alex Massie on this. This is in contrast to the British system; although MPs have frequent surgeries, a sort of open house for constituents, they aren’t incentivised by a permanent campaign system. The American electoral process sometimes looks like theater, with the people vying for one of the world’s most powerful and pressured jobs try to qualify themselves by scarfing fried meat at fairs they would never otherwise attend. Still, it provides regular reason for politicians to pay attention to polls and to protests.
There shouldn’t be any schadenfreude in this; there are plenty of problems with the American media. But this should be a reminder that dissent is patriotic, whether it comes from the tea-party movement or the netroots. We can bemoan the incivility of the discourse, but we should also see the occasional virtue of our fractious discourse and of our partisans howling and forwarding emails in the middle of the night, whether they’re in San Francisco or Salt Lake City.