The black letter law says:
Each house may punish as a contempt, by imprisonment . . . for one or more of the following offenses: . . . prevent[ing a] member from voting.A petulant Republican State senator says:
— Wisconsin Statute § 13.26
[A]ll 14 Democrat [sic] senators are still in contempt of the Senate. Therefore, when taking roll call votes on amendments and bills during executive sessions, Senate Democrats' votes will not be reflected in the Records of Committee Proceedings or the Senate Journal. They are free to attend hearings, listen to testimony, debate legislation, introduce amendments, and cast votes to signal their support/opposition, but those votes will not count, and will not be recorded.A Wisconsin Supreme Court justice says:
— Sen. Scott Fitzgerald
[W]hen a citizen votes in a judicial election, he or she exercises a right guaranteed under the First Amendment of the United States Constitution. Protecting the First Amendment rights of all voters to cast votes that could not later be cancelled by the acts of others was a primary concern of the court in the rule that was enacted.Roggensack was referring to a rule governing the recusal of judges in cases, but the fundamental constitutional principle is the same and applies equally to Fitzgerald's Diktat. She meant that when a judge is excluded "by the acts of others" — as opposed to of their own volition — from hearing a case without what in Roggensack's view is good cause, the voters' First Amendment rights of speech and association are abridged, in that their elected representative judge is silenced.
— Justice Patience Roggensack
And a majority of the court — the so-called conservative bloc — concurred with Justice Roggensack's own vote in enacting the rule.
Strictly speaking, Scott Fitzgerald isn't preventing the 14 Democrats from voting; he's letting them vote. He's just refusing to count their votes, an "act of others" which is little different from preventing their votes, if "voting" is to have any meaning at all in § 13.26.
While each branch of government's self-regulation is to some extent immune from the scrutiny of any other branch,* none of the branches may violate the 14th Amendment — it makes the First Amendment binding upon the States — which regulates the operation of all three.
In other words, it's one thing to be found in contempt (and "disorderly behaving") according to some application of Robert's Rules of Order to a political squabble within the legislature, but it's quite a different thing for a legislative leader to be contemptuous of the Constitution.
And while the Wisconsin constitution empowers Fitzgerald and his conservative Republican allies to mete punishment against their colleagues, no constitution empowers them to punish citizen voters.
On the other hand, Fitz's noise is sweet music to recall organizers.
* And in some instances even immune from itself, where the statutes expressly authorize their own subjection to parliamentary rules.