Benghazi. A CIA gunrunning scheme that went bad and led to the deaths of four Americans. A stand down order that had to come from the president himself. A major lie about the nature of the attack, blaming it on a video, the creator of which has been disappeared by the government, because the First Amendment means nothing when Muhammad is involved. Treason, by definition of the Constitution. The single worst thing any president has ever done, ever, by a lot.
The IRS being used as a weapon against conservative and small government political groups in 2010.
Even the far left MSNBC agrees, the government does not tread on political speech. As Joe Scarborough says "political speech is sacrosanct." It doesn't matter where on the political spectrum you are, this is a gross violation of federal authority and heads must roll.
To top it all off, the Justice Department has been illegally spying on the Associated Press. The records from more than 20 separate phone lines used by over 100 AP journalists and editors were seized by the DOJ.
Any one of these is enough to warrent impeachment. Obama has all three. IF he survives this, it will mean he is a de facto absolutist dictator. No one will do anything to stop him from running for a third or fourth or life-time term as ruler of the country. IF he survives this, there is no justice.