The jungle special election is unique, and helped KBH get elected to her Senate seat in 1993, after Clinton appointed Senator Bentsen to his Cabinet.
Ann Richards appointed Bob Krueger to be the interim senator, and a ton of people ran against him in the special election. Reps. Joe Barton and Jack Fields split the conservative vote. KBH and Bob Krueger got into the runoff, where Kay creamed him. It could be argued that KBH could not have gotten out of a standard Republican primary and runoff.
Once she became an incumbent Senator, no Republican of any stature opposed her.
It has been argued that John Tower would never have been a Senator without the same setup.