Yes. They challenge it by declaring EP, idiot.And the Executive branch has the Constitutional authority to challenge them.Separation of powers, dumbass.No it isn't, dumbass.
What do you call it?
That means nothing. Congress has the constitutional authority to subpoena materials and testimony.
Oops!
So, according to you, the sitting President can NOT challange subpeona's in court less they committ obstruction of Congress? Really? Is that what you want to go with?
Becuase there are plenty of cases in not only the Obama administration doing the exact same thing, but indeed throughout the history of sitting Presidents going all the way back to Washington...So, what makes this different?