In part it was because lots of other blogs did, and also because things were so frenzied building for the May 1 immigration rights march that several topics for blog posts just slipped away.
It was a watershed moment though, and reminds me of an incident during the Watergate days when Nixon was finally weakening. For months, no one criticized Nixon in the mainstream media. Then, one day, Johnny Carson, who then had a hugely popular late night talk show on TV, made a tiny, mild anti-Nixon joke. The audience laughed.
The next night he let Nxon have it both barrels. I thought at the time, ok, Nixon has lost the heartland, as Johnny Carson and his gagwriters made a point of reading midwest newspapers daily to see what folks there were thinking. For Carson to make a joke like that meant something had shifted in the American psyche. From then on, it was seriously downhill for Tricky Dick.
This is not to say that Johnny Carson had the power, and neither does Steven Colbert, but rather than the times had changed enough that such public mocking finally became possible.