At The Monkey Cage, Patrick Egan has put together a nice chart showing viewership of the cable news networks on the night health care reform passed compared to their ratings of the prior weekend:

I’m reluctant to draw any conclusions from this information about the relative levels of enthusiasm/anger the bill is engendering among different constituencies. And it’s important to note that this chart measures the spike at each channel against its own ratings standard, which is much higher for Fox News: CNN didn’t actually surpass Fox in total viewers until the 11 p.m. hour (and MSNBC never did).

Still, it’s a nice demonstration of the point Matthew Yglesias makes: “when actual news is unfolding on television, the American public”—or at least that considerable portion of the public which does not normally spend its time watching cable news—“prefers CNN.” Unfortunately for CNN, that’s not very often.

Update, 3:12 p.m.: To continue cribbing other people’s work, Yglesias has now created this chart using direct viewership numbers:

As the chart shows, at least in this instance, Fox’s normal ratings dominance became parity with CNN when news was being made, with MSNBC far behind.