If Clinton had resigned or been pushed out, it would have set the precedent, and the demand, for the Republican leadership in Congress to be brought up on charges of various sorts. It wouldn't have been easy for Gore (or anyone) to work in such an environment. They were trying to tar Gore with the same brush (remember the Buddhist temple stuff?).

A President should only be removed, or leave, when he doesn't have some support of the people and some of the Congress. Clinton's support among the people was very high at the time, and the Democrats weren't pushing for him to go.

We got 8 years of Bush for various reasons - impeachment wasn't the biggest of them, IMO. Gerry, Jimmy, and GHWB show that it's not that difficult to remove a sitting President if the conditions are right. It doesn't take a disaster - Gore probably would have had trouble keeping the job.

Cheers,
Scott.