I believe it would be far easier to use a procedural device to rule the filibuster out of order by using a ruling from the chair. The bottom line is that this is a procedural matter of the Senate. No federal jurisdiction.
As I indicated in my post, Cornyn himself is trying to piece together a panel of Constitutional experts to argue that the use of filibusters to obstruct otherwise slam-dunk nominees IS un-Constitutional.
Ah, but as I pointed out last week, Cornyn screwed up last week when he said that the SCOTUS does not have jurisdiction. The problem is, if the Senate procedures are unconstitutional, the Courts DO have jurisdiction--automatically so. All the Courts need for intervening is a triggering action. (Maybe most courts would be reluctant to rule against the Senate rules, but that would be a matter of dereliction of Constitutional duty on their part, not a matter of lack of jurisdiction.)