Here's a written piece where the author spells out what the 'fundamental legal flaw" might be in the indictment, including that the law as Bragg is trying to apply it would be unconstitutionally vague:
No one knows if Donald Trump can be prosecuted for the hush money payment to Stormy Daniels.
www.vox.com
These arguments against the indictment on legal grounds by Yoo, Epstein, and Millhiser are reasonable, I think, on their face (again, I am not familiar with the case law in this area, either NY or fed, so maybe these arguments are foreclosed somewhere).
I'm not arguing that these defense arguments will win or that my own political philosophy supports their winning; I'm just commenting on them from a legal generalist perspective.