Senator Lautenberg (D,NJ) will die in office this year. The NJ legislature will attempt to force the Governor to appoint a Democrat to replace him.
The NJ media will agree. The NJ supreme Court will interpret the Constitution to agree as well.
I think it’s Leahy who will have health issues. He’s old too, and he hasn’t looked all that great in a while. Having so much hatred and meanness inside isn’t good for the body. It would be surprising if Leahy can go much longer without negative physical repercussions of some kind. [Not that I wish him ill. I just wish he’d retire—along with most of the other ancient congressional fixtures.]