This needs to be done NOW

JD Vance could take over John Thune's spot as Presiding Officer in the Senate:

Thought for 6s

Yes, JD Vance can take over the presiding officer role (President of the Senate) from John Thune or others at any time he chooses.

Constitutional Presiding Officer (President of the Senate): Article I, Section 3 of the U.S. Constitution designates the Vice President as the President of the Senate. Vance can enter the chamber, assume the chair as presiding officer, and exercise those powers (recognizing speakers, ruling on points of order, and casting tie-breaking votes) whenever he wants.

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This does not require Senate approval.

Senator Mike Lee has publicly confirmed: “JD Vance can come to the Senate ANY TIME he wants and immediately assume the position in the presiding officer chair.”

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In practice, VPs rarely preside full-time (they usually appear for key votes), but there is no barrier to Vance doing so more actively.