The Senate—which is a co-equal branch of government—has every right NOT to confirm
They aren't required to confirm, they are required to vote.
Really?
What proviso requires a vote
The senate has already
ADVICED the POTUS that they will not
CONSENT. What am I missing?
The Senate must give Advice and Consent (up or down) to the President as required by the Constitution. That means a vote, which is how they do such a thing unless you'd like them all to sit down to tea together?
"[The President] shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the
Supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments."