The obvious answer is all the way to the top. The only person served by the soiliation of evidence at the IRS, EPA and FEC is Barack Obama. A criminal convcition can be sustained on CIRCUMSTANTIAL EVIDENCE. there is enough of same to convict Obama, or at least drive him from office, if all the Rs would get on Palin's page. Direct evidence is not required.
If you put the soldiers in prison, they will give up the Capos. If you imprison the Capos, they will give up the Don.
"High crimes and misdemeanors", like "good behavior" for judges, was deliberately left vague by the Founding Fathers. They understood that no number of laws or procedures could define or prevent all cases of the calamitous abuse of power, so wrote in a political safeguard.