There was just one of the most telling exchanges of the whole hearing.
Sen. Chuck Schumer (D-NY), up for another round of questioning, declined, saying that Alberto Gonzales had failed to meet the burden of proof to explain the basis for the U.S. attorney firings, and to show that they weren't improper. It wasn't worth trying another line of questioning.
Gonzales shot back, saying that he'd explained his own actions, and that the burden of proof was actually on those who had alleged that something improper had happened here, i.e. Sen. Schumer and others.
Schumer replied: "Our standard is not a criminal standard -- it's higher than that." Because Gonzales had fired the U.S. attorneys, Schumer said, the burden is on him to give a full and complete explanation for the firings. He hadn't done that, he said.