PEOPLE ARE TALKING ABOUT THE SENATE EXCLUDING OR EXPELLING ROY MOORE IF HE’S ELECTED. Under Powell v. McCormack, Congress’s only role in seating members is to ensure that they meet the Constitutional requirements of age and residence. On expelling members, here’s what it says:

Nor is the distinction between exclusion and expulsion merely one of form. The misconduct for which Powell was charged occurred prior to the convening of the 90th Congress. On several occasions, the House has debated whether a member can be expelled for actions taken during a prior Congress, and the House’s own manual of procedure applicable in the 90th Congress states that “both Houses have distrusted their power to punish in such cases.” Rules of the House of Representatives, H.R.Doc. No. 529, 89th Cong., 2d Sess., 25 (1967); [p509] see G. Galloway, History of the House of Representatives 32 (1961). The House rules manual reflects positions taken by prior Congress. For example, the report of the Select Committee appointed to consider the expulsion of John W. Langley states unequivocally that the House will not expel a member for misconduct committed during an earlier Congress:

[I]t must be said that with practical uniformity the precedents in such cases are to the effect that the House will not expel a Member for reprehensible action prior to his election as a Member, not even for conviction for an offense. On May 23, 1884, Speaker Carlisle decided that the House had no right to punish a Member for any offense alleged to have been committed previous to the time when he was elected a Member, and added, “That has been so frequently decided in the House that it is no longer a matter of dispute.”

I assume the same would apply to the Senate. I’m not sure if this is dictum or not, since the Court was (sort of) deciding whether Powell’s exclusion could also be interpreted as an expulsion, but it’s pretty on-point.

UPDATE: This piece takes a contrary view.