Cohen wants a pardon.
Trump could just send him a signal that it will happen, but Trump is a belligerent bully with a really psychopathic need for dominance, so he won't do it.
So, Cohen is ratcheting up the pressure, step by step, trying to get Trump to give him what he wants.
Trump is counting on his followers to not give a damn how many prostitutes he had to pay off, or how many of them had abortions, or any other damned thing.
After the shocker about the tapes, we can be pretty sure that what Cohen has revealed so far is only the tip of the iceberg. The only question is whether Trump will be manipulated by other Republicans into pardoning Cohen before Cohen reveals something that really does damage Trump. Or if there is any way to make Trump supporters ashamed of what they have done, since sucking up to a foreign dictator isn't enough.