They knew from the beginning that he couldn’t be indicted but he should could be impeached. They wanted to get enough on him to let an impeachment go forward. Doesn’t look like they succeeded. No matter how much Maxine Waters or Al Green may long for an impeachment, it goes nowhere without public support. At this point, they’re stuck with the CBC and a few more lefty Dems in support of impeachment, nowhere near what they need.
Much like Patrick Fitzgerald knew from day one that Valerie Plame was not covered by the Intelligence Identities Protection Act and that Richard Armitage was the one who, entirely legally, revealed her name.