Paying off a hooker out of campaign funds.
I thought it was a campaign funding issue ?
That's not exactly what happened.
I explained Trump's potential crimes back in post 8174. I'll go into a little more detail here.
(Note however that at this point we won't know what he is getting charged with, or what evidence they have, until the actual indictment is made public and Trump is actually in court. These seem to be the most logical suggestions.)
There are a couple of areas where Trump might be in legal jeopardy...
First of all, there is a potential campaign funding issue, but not in the way you suggest (with him misusing election funds).
If it was revealed during Trump's campaign that he had an affair, it had the potential to harm his election chances. Thus, the payment to Stormy Daniels to keep her from talking would have improved his chances of winning in 2016 and thus could have been considered a campaign contribution.
All large campaign donations need to be tracked, even if it is a politician "donating" to his own campaign. (Why? likely because they want to limit the ability of donors to "buy" politicians.) So Trump's $100k+ payment should have been registered. But it was not.
This is not some unique, never before seen crime. In fact, this was one of the reasons Trump's previous lawyer Cohen went to jail.
The second issue is that the payment was (probably) made through the Trump organization (rather than a payment from Trump's personal accounts). Now, Trump may be the main owner of the Trump organization, but even the sole owner of a company cannot use the company as their personal piggy bank, making it pay for personal expenses. (Why not? Well, there are tax implications for one.) Trump supposedly had the money paid to Stormy Daniels listed as "legal expenses" in the Trump Organization's books. Since Stormy Daniels is not a lawyer, and she was not working for the Trump organization, then the Trump organization paying her off under the guise of "legal expenses" was fraudulent.
And just like the issue of campaign finance, this is not some new invention, some never-before-seen prosecution.
Trump COULD have paid off Stormy Daniels in a way that was 100% legal... he could have 1) taken money out of the Trump organization (perhaps as a salary increase or bonus, with whatever income tax implications are involved) to pay her from his own bank account rather than the Trump organization, and 2) when he paid her off, properly listed it as a campaign contribution. But Trump did not do any of that. And thus the reason why he might end up facing real, criminal charges.
Now, given all the crimes he has committed, this seems like pretty small potatoes. (I would much rather see him jailed for document theft and bank/tax fraud.) But still, he broke the law. Others have been jailed for the same sorts of crimes. And saying "Trump should be given different treatment because he's more famous, or he committed bigger crimes so we should ignore the small stuff" flies in the fact that "everyone is equal under the law".
There may be other laws that were broken too... There may be legal restrictions on companies financing and coordinating with election campaigns. There may also be some perjury or tax fraud charges thrown in there as well (although as I said before, we will have to wait and see whatever charges are included in the indictment.) And given Trump, it would not surprise me if they added things like Witness Tampering (based on his call to protest over his indictment).