I don't claim to have any legal expertise, but I don't see anything in the Cohen plea that could get Trump in serious legal trouble. Cohen pleaded guilty of making an illegal campaign contribution, at Trump's request. I would think any jury would understand that the hush money was coming out of Trump's pocket, not Cohen's. For goodness sake, Trump was his client. Lawyers don't usually spend their own money to help a client. They bill it back to the client. There is nothing illegal in Trump spending his own money for his election. And nothing illegal in covering up his tracks while paying the hush money.
Most likely Cohen was pressured into wording his guilty plea that way so the prosecution could claim some points against Trump. Yeah, it will cause some political problems, but I think that's about all.