Her big scandal at TNR - though it wasn't what actually cost her the job because lol - was a huge very racist article about personnel practices at the Washington Post, which fit very much into the very popular-in-the-90s genre of "black people get all the breaks," especially popular with New Republic editors named Andrew Sullivan.
This David Carr piece is, I think, too kind, and also requires some reading between the lines as Carr's pieces always did (he knows more than he says).
As I said, she didn't just depart "journalism" without looking back. She went on to have mini-scandals at Elle and Salon about things no one much cared about. And, here she is, hired again! Some people's talent is just so indispensable.