Still, that tape of Trump and Cohen discussing the payoff was fun, wasn't it? It revealed another Trump lie, which we knew to be a lie anyway, it probably shows a campaign finance violation, and those aren't even the good parts. The good part is this: Trump has a real Michael Cohen problem. Cohen has dirt on him. More than just this. How do we know? He was Trump's lawyer, and Trump is really corrupt. There's more. Is there good stuff? That is difficult to say, since the good stuff is Russia stuff, and Cohen wasn't primary to the campaign, but Cohen was involved in paying off women, sending goons to threaten daughters, and things like that. There's dirt. Cohen is facing his own charges. What's Trump to do?
The problem is this. Trump's obvious way out is to pardon his way out. To borrow from Jackie Brown, Cohen ain't got a doin' time type of disposition. The normal way of handling a political pardon situation, though, is to do a little time, and then get your pardon. Cohen is just a twitchy little bugger. He wanted that pardon immediately, and he couldn't keep his cool the way Flynn appears to be doing. So, Cohen is flipping. How much has he already given up? That's the problem. If he has already given up everything he has, there is nothing to be gained by pardoning him, but if he still has dirt he hasn't given Mueller, then Trump's rational move would be to pardon Cohen despite the pride he'd have to swallow.
For Trump, though, loyalty to Trump is everything, and that creates an issue for him. Now that Cohen has clearly crossed the line and flipped, at least partially, Trump isn't personally capable of swallowing his pride and pardoning the guy, even if it is the rational move, which he can't confirm anyway because he doesn't know how fully Cohen flipped. That puts Trump's vengeance motive against his self-preservation motive, and for Trump, vengeance will always win out.
And in this case, he always has the option to pardon himself anyway, and congressional Republicans will never let him be impeached, so this is just all about two douchebags trying to get back at each other.
Given Trump, then, Cohen played this badly. If he wanted that pardon, he needed to keep his mouth shut, do just a bit of time (no more than a year, if that), and then get his pardon. Once he shows disloyalty, though, Trump can't bring himself to pardon the guy. At this point, it isn't even clear that he should because Cohen may have already given everything to Mueller, in which case Trump gains nothing by pardoning him, and since he is guaranteed to get away scot-free anyway, how much is vengeance worth to him, and how much does he gain by preventing some embarrassment by shutting Cohen up, if he still can?
And Trump? He misread that little twerp, who "ain't got a doin' time type of disposition." Should he have just pardoned him immediately? If he had done that, he would have faced an immediate demand for a pardon for Flynn and Manafort, at which point he would have needed to fire Rosenstein and bring in some flunky to replace Mueller, and then call it a day. Cohen just threw this whole thing into Trumpian chaos.
Now, take this all with many crystals of sodium chloride, but preferably not a bath salt. After all, it doesn't really matter what Cohen says, for our politics today. Cohen could have a copy of the golden shower tape, and hand that to Mueller. It still wouldn't get a single Republican in Congress to turn on Trump, and that means impeachment will never be on the table.
Like I said, this is just about two douchebags trying to screw each other over. The good news is that at least one douchebag will be worse off at the end of this.
And I might as well add this. Trump and his people say the tape was doctored. Would Trump hire a guy as his lawyer who would doctor a tape? Yes. Yes, Trump would hire that kind of guy as his personal lawyer. At the same time, when you imagined what was on that tape, wasn't that pretty much word-for-word what you expected?
Two douchebags.