I am wondering if the Democrat Senators are illegally striking. I think you might be able to make a case, either way.
Partly their actions should be seen in the historical context of how representative democracies work. It is not without precedent for legislators to shirk their responsibilities. But I think it would also be instructive to examine the reactions of the voters in those cases.
It seems to me that if the voters agree with those strikers, then no sanctions will be forthcoming. But if the voters don’t like it, you can be sure they will act at the ballot box.
My guess is that a lot of these strikers will be fired by the voters.