Stephen Sachs:

According to his official website, California Gov. Gavin Newsom on October 1 appointed Laphonza Butler to the Senate, to complete the term of the late Sen. Dianne Feinstein. Butler was apparently a Maryland resident as of very recently, but according to Newsom’s office she plans to re-register to vote in California before her Wednesday swearing-in.

For various reasons, though, that might not be enough, and the Senate will have a real constitutional question to face. As far as I can tell—and I’d be happy to be corrected—if Butler hasn’t traveled back to her home in California since deciding to take the job, and if Newsom doesn’t wait until she does to make (or re-make) the appointment, she can’t represent California, and the Senate can’t seat her yet.

(NB: This isn’t my area of expertise; I usually just listen to Josh Chafetz on most questions of Congress’s procedure and structure. But I’ve been working on a paper on the Twelfth and Seventeenth Amendments, which is why these questions came to mind. Also, nothing in what follows turns—or should turn—on one’s political agreement or disagreement with either Newsom or Butler.)

Why would Butler’s residence matter? The Constitution establishes the following qualifications for Senators in Art. I, § 3, cl. 3: