Former national security adviser Charles Kupperman's lawsuit asking a court to decide if the House's subpoena for him to testify in the impeachment inquiry is valid/enforceable has been assigned to Judge Richard Leon in DC 
Leon brings a uniquely relevant background — before becoming a judge in 2002, he advised Congress in multiple investigations involving presidents. He's also a former DOJer. He's a Republican by background, but he is definitely not always a predictable vote by that metric
For one thing, you may recognize his name most recently as the judge who ruled against the Trump administration in approving the AT&T-Time Warner merger: buzzfeednews.com/article/daveya…
One of his most famous decisions came in 2013, when he issued a preliminary injunction blocking the NSA telephone metadata collection program in the aftermath of the Snowden disclosures: usatoday.com/story/news/nat…
He can also be quite tough on government lawyers. The Kupperman case presents all sorts of interesting dynamics because the Trump administration and House Dems are all defendants, as opposed to this being another case where Dems are suing Trump or vice versa
Anyway, this is not to say that Leon is a liberal in disguise — he's considered one of the more conservative judges on the DC bench. This is just to say that he has a varied track record, so to say he's a "W. Bush appointee" and end the conversation only takes you so far
The judge handling former natsec adviser Charles Kupperman's subpoena lawsuit has set a status conference for Thursday (10/31) at 3pm. Another judge in the same courthouse will be hearing arguments at 2pm in the Don McGahn subpoena fight.
