Just a couple of important considerations:
1. Comey could only be prosecuted for leaking classified information to the media if the information he leaked was TRUE. The problem in this case is that proving that the information in his memos was true would likely require testimony from President Trump. That's never going to happen.
2. There's a legitimate question about whether those stupid self-directed memos were even official FBI documents anyway -- regardless of whether they're true or not. Comey didn't prepare them on behalf of his superiors, and wrote them to himself and gave them to the media apparently without sharing them with anyone internally at the DOJ.
I disagree for this reason: even if they couldn’t “get him” (a conviction) they must begin indicting these people & force them to burn some wealth just as they did to all of Trump’s people.