It indeed doesn’t seem right that the same candidate be on the same ballot for more than one ‘Federal Office’. Though unlikely, imagine if the same candidate got nominated for a congressional district, senate, and president all at the same time. What if they won all three? lol That’s a sloppy way of doing things. The winning candidate would choose which office they wanted, and the governor would appoint for the other two, effectively taking away the vote from everyone that participated in those other two elections, until a special election happens anyway.
Not how it should be done. If you’re gonna run for higher office, you owe it to your constituents, and others who may want to run for it; to vacate your seat.
Bob Dole resigned, although he didn't have to.
McCain did not resign because he didn't have to and he is a scumbag.