What makes a scandal scandalous? Why do some stories stay on the news every single night while others disappear? Are the current events just more of the same "run-of-the-mill-gates" that do not actually matter? (Hint: Yes, they are.)
As Nate Silver addresses all those complicated questions, I'll address the opposite: What is NOT necessary for an event to become a political scandal?
1) A major public figure was directly involved.
If you think that the person being blamed for the scandal on cable news MUST have had anything to do with the events that took place, then you would be wrong. Leaders are not responsible for absolutely every little thing that happens under their watch, especially the things they have no control over. Hillary Clinton is as responsible for terrorists attacking the US Embassy in Benghazi as George Bush is responsible for terrorists attacking the twin towers in Manhattan (or any of the 11 Embassy attacks that happened while Bush was President). As most people understand this general concept, the public trusts Hillary Clinton more on Benghazi attacks than the Republican party.
Likewise, Obama has no control over lower-level civil service employees in this whole IRS affair. Our Constitution creates such a strong separation between the executive branch and bureaucracy that Obama could not even fire the employees responsible. He could ask for the acting director to resign for poor oversight, because that is a politically-appointed position. So that is what he did.
2) Reasonable time frames are allowed for.
Information 24 hours after traumatic events is unclear at best, if not a complete and utter mess. For example, the FBI did not know who the Boston bomber was until three days after the event. Information was unclear in all of these events. Should President Bush be accused of a cover-up for not knowing what happened immediately following September 11?
President Obama learned of the IRS scandal the same way the rest of us did, by seeing the IRS apologize for it on the news. When the Investigator General's report came back on the event, it revealed a whole lot of nothing. No real scandal. No real cover-up. Nothing really to apologize for. Just a government process that needed to be cleaned up. But by that point, it was too late. The headline was already-made by then. It was the "IRS targeted conservative groups". Not "IRS unsure over 501(c)4s. No conspiracy."
3) The accuser has the moral high ground.
When Democrats criticized Bush for anything security related, Republicans criticized them for politicizing a tragedy even though they were the ones who used 9/11 footage in their campaign ads. That has not stopped them from attacking Hillary Clinton over a different human tragedy as well as matters of national security. Whatever happened to these accusations aiding and abetting the enemy? How hypocritical.
Civil Service employees under George Bush went after opposition-aligned third party organizations because the civil service believed that these organizations were partaking in illegal activities. Conservatives trumpeted when this happened instead of saying that is was unfair to Democrats. How hypocritical.
And yet, I doubt this is going away any time soon.