"But, I imagine it would be the Executive Branch that would have standing, and so, I don't see why the matter couldn't be adjudicated quickly in an application for mandatory injunction- or writ of mandamus- petitioning the District Court to compel the Senate to fulfill it's obligation under the Constitution."
Pretty doubtful a District Court, or even the Supreme Court would vote to compel Congress to act in a particular manner.
I would predict the courts would let Congress work out their internal rules by themselves. IOW if the Senate doesn't have the votes to change their rules, that's the Senate's prerogative.
So it rests in the hands of Senate leadership, and perhaps the persuasive skills of the President. As for the troubled nine, their pet projects and issues need not see the light of day.
And some may arguably be looking to a future time, when Republicans would wish to block appointments.
Another point about Fortas ,he was already a supreme court judge,he was nominated for chief justice .
Seeker-
I essentially agree with your points.
My comment was based on the query put to me by Jack Bull, who posits that there exists a potential legal argument (above) that could be framed as to the constitutionality of the filibuster, mirroring the authorities that found the the line item veto unconstutional.
Without research, and having not read his cited authorities, I only suggest a way it could be advanced in Court- but agree, my cursory opinion is that it would likely fail.
As for your comment, ‘some may arguably be looking to a future time, when GOP would wish to block appointments-‘ that is likely true.
But, for himself, a conservative with a populist streak, I disagree with those who hold that view. During a Presidential election, one of the issues that is invariably put to the voter is the fact that the winning candidates enjoys the prerogative of appointing justices. IMO, the Senators have a right to oppose the nominations, but not to use a filibuster to block the nomination- that would go for either party.