Ok, so, not being 'murican, would there be a special election and if so is this what we'd call a 'safe seat'? i.e. if he croaked it'd be a shoo-in Democrat replacement?
Or does it go state by state and depending on which system this state uses it appoints some successor to see out the term without an election?
Curious because having taken control (aiui) of all three of presidency, senate and congress, they may actually get something done. Whereas if they lose one then it's obstacle city trying to get anything actually done ...
Clearly I know a bit, I'm a big fan of The West Wing, but I'm no scholar on the US system (in honesty I'm pretty ropey on ours I probably need a few lessons with our in-house estimable history teacher @RoverAndOut)