Steve Bannon, who looks more like a homeless man than anybody who has ever worked in the White House, is as much of a right wing loon as Donald Trump. So, there’s no particular reason to assume that what’s in his book is true, other than the fact that there has been plenty of nutty stuff going on in the Trump administration and there would be no reason to make stuff up when he’s undoubtedly got great material to work with. Trump, for his part, is trying to block publication of the book, which probably indicates not only that most of the stuff is true, but it’s also damaging.
That also shows that Trump doesn’t understand the law, but that’s no surprise.
The thing that I wonder about is what could possibly be in the book that Trump thinks could be damaging. Examples of how Trump didn’t understand foreign policy/domestic policy/the Constitution/basic science would not damage him with his base and wouldn’t surprise anybody at all. Stories of how horrible he is to his wife/his staff/his limo driver are going to be dismissed as old news. Racist statements, obscenities, sexist innuendo will all be old hat. Tales of how he passes up on the offerings of a world class kitchen to stuff his face with KFC and Doritos will just be regurgitating what we already know.
Some impeachable offense? Hell, there are already lots of those. The reason he hasn’t been impeached isn’t because there’s no cause. There was cause after the first weekend at Mar-a-Lago. He hasn’t been impeached because almost everybody in congress is complicit. They may shout a bit, but they won’t do anything.
Barring a sweeping change in congress in the 2018 elections – which the Democrats are trying like hell not to accomplish – he’s going to finish out his term.