When I read that Menendez resigned today, as of 8/20, I decided to do some research. This is what I found.
I counted all the Senators at https://www.senate.gov/senators and found that the Dems have 47 Senators. Rep have 49 Senators and Independents have 4.
So my question is this...If we have more than the Dems why is Schumer the majority leader?
The answer in my conspiracy mind is that the Dems don't give two hoots about the law and the rules and know that until they are out of office they can do whatever they want to do.
But, I may be wrong. There be something I don't know about the calculations for Senate Majority Leader.
I believe at least Tulsi Gabbard switched out from the democrat party.
Tulsi Gabbard is no longer in Congress
OP was asking specifically about the Senate - Tulsi Gabbard was in the House
Ahh my mistake