Bad behavior has been around forever, but shame has historically kept the behavior in check by operating as a warning mechanism not to transgress in the first place or, if that fails, triggering consequences for transgressing.
Part of the popularity of the shameless leader derives from the fact that there is no pretending any more – the id is unmediated and allowed free rein. There is a sense that this is the real person. All the rest of them – Obama, Blair, even Bush – spoke with a degree of civility and convention that is now missing in public life. Often that civility hides a multitude of sins. Now the sins are still there but no one is trying to hide them, and no one feels ashamed when they are challenged about these sins.
Lack of shame has also short-circuited a traditional role of the media, whose power we have realised is largely to shame public figures by exposing things.
The expectation is that the subject will feel so ashamed by the exposure that they will quit. But then if they don’t quit and the public re-elects them, the media is exposed as being impotent.
The Media itself lost its way by siding with someone over the other, elaborate of one sides story over fair representation. In the process blame others for being shameless.