I wouldn't worry too much.
If (I mperial Presidency) George W. Bush wasn't able to pull it off even with the help of Cheney, it ain't going to happen. Executive Privilege has been with us since Jefferson. Every President has either invoked it or worked out a compromise between the Office of the President and Whatever Committee of Congress was seeking records, testimony or both.
I thought George W. Bush would invoke it when he was asked to testify before Congress regarding the attacks of September 11th, but he didn't. He worked out a deal where he would know each and every question that was going to be asked, he still sweated through the whole process like he was the head of a Mexican Miracle Cure Bureau being interviewed by Mike Wallace.
Issa is a creep who should be in prison for various frauds. If I were him, I would keep my head down.....but come on, idiot, expose yourself.