So, what did the Senate Judiciary Committee learn from former White House political director Sara Taylor yesterday? Ostensibly, the hearing was about the Bush gang’s role in the U.S. Attorney purge scandal. Taylor agreed to appear, despite the White House “directing” her not to cooperate, under a dubious claim of executive privilege.

It led to the worst of both worlds. Taylor honored a subpoena (which was good), but honored Bush’s suspect claim to executive privilege (which was bad). She ended up repeatedly telling the senators that she couldn’t remember, couldn’t explain, or couldn’t talk about anything of interest. She invoked Fred Fielding’s name 24 times, and mentioned his letter about privilege 35 times.

But even more annoying, as Slate’s Dahlia Lithwick explained, was that Taylor was selective when it came to what was privileged information. In short, when she liked the question and wanted to answer it, Taylor testified. When she didn’t, she claimed she was forbidden from speaking.

At first this pattern of half-compliance with the subpoena just confuses the senators. Chuck Schumer, D-N.Y., huffs that “the fact that you are answering some questions but not others weakens the executive privilege claim even further. It shows how specious their claim is.” But later, Ben Cardin, D-Md., and Leahy begin to observe that in fact Taylor’s notion of the executive privilege seems to be that she can testify at length to exonerate friends at the White House, then clam up when she might implicate them. As Leahy growls toward the end of the day, “each time the finger points at you, you hide behind your oath to the president.”

After yesterday’s developments, Pat Leahy asked, “What is the White House trying to hide?” Apparently, quite a bit.