I'm sure it would go to court, but it wouldn't be heard until after the mid-terms and Trump's base would be energized by the defiance.
-PJ
I didn’t think about that. Congress has no authority to subpoena a President for anything that occurred during his presidency.
Impeachment is the House’s recourse against a sitting President (or even after he’s left office, I guess). They tried and failed to convict him. Subpoenaing him to a committee is a clear violation of the Separation of Powers.
A court should quickly throw this out if it follows the Constitution.