And then, there's Benghazi. Clear case of treason, and no Democrat is interested.
Clinton clearly dropped the ball with Benghazi. Her negligence had fatal consequences, and her apology did not sound sincere. However, I would not call what she did "treason:"
Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court.
She was negligent and failed either to provide additional support for the consulate or authorize their withdrawal to a safer location. She did not levy war against the United States, nor did she adhere to or provide aid and comfort to an enemy of the United States. She was a spineless coward who clearly did not respect her subordinates or value their lives: but she did not commit the crime of treason. I think in general some people throw that word around a little too loosely without understanding what it means.