But not his seat. If Johnsons disability turns out to be long term then no doubt the Democrats will replace him in any leadership positions he may have but he'll still be a senator. I don't think that the GOP allowed Strom Thurmond anything other than ceremonial duties his last four or five years.
There wasn't such a fight with Strom. In that case, it was Strom who wanted the seat. The truth is, it is nearly impossible to expel a sitting Senator, no matter how invalid.
But this case isn't similar to Strom or when Biden was out with his surgery. There is a very real possibility that Tim Johnson will never be able to function at all. Strom could at least be wheeled into the chamber, at the end.