Question on Replacement/Early Elections

Ok, right now it seems a bunch of republicans are gonna end up in jail. Some like ROve weren't elected but placed by Cheney into power. But Some, like Delay and Frist, were elected into power. So what happens when they go to jail? Do the districts/states they represent have elections then and there, wait till the 2006 elections, or do the Republicans get to place anyone they want to replace the person sitting in jail?

Some of it is up to the state government, I think what happens in most cases though is that the Governor of the State will appoint a replacement. This can lead to Democrats filling a Republican seat, etc.

I don't expect Rove, Delay, or Frist to go to jail tho.

There isn't a "chain" like with the presidency? I honestly don't know, but that would seem somewhat logical: have a "vice senator" for example, never does much of anything, maybe administrative support stuff, but they've been around through the term and know what's going on.

At a guess, I think it'd go down to the next in line. Whoever won "Second-Place" in the election or at least, that'd be the common sense way to do it.