Congressional rule question

[democracyindanger]

Anybody with a good grasp of US Congressional rules got an answer to this?

Let's say, hypothetically, that a number of Republican senators and representatives were found to have gained office through fraud. Naturally, they're thrown out. Does this open the door for their votes on bills--made while they were in office illegally--to be thrown out, retroactively? And if the resulting vote count means that the bills didn't have enough votes to pass, can the bills be nullified?

Just some wild, Saturday afternoon thinking. Anybody know?