Broad claim?
No, it’s a rather simple one. He has Constitutional rights just like everyone else.
If there is known criminal activity, a subpoena can be obtained, but there is no evidence.
This was a fishing expedition and everyone knows it.
Correct! They (left wing prosecutors, Democrats) think if you can’t find evidence of crime, go after the tax returns. That is how they got Al Capone. They under-estimate Trump.
The question is whether a President can ignore a subpoena.
The ones Trump's fighting have already been issued.
In this case the Dems are hoping they can find something and that’s why they are so hell-bent on getting it. They have no evidence of any wrongdoing so it is really a fishing Expedition. SCOTUS should side with him on this case. Their goal is not just prosecution but to find anything they can spin or use to embarrass Trump politically.