"If the other side is about to pass a horrible bill...
...then they'll get royally screwed in November, and they know it."
I wish that was true, but I don't think it is. Assume a RINO Congressman votes for amnesty. What are the voter's choices? A RINO or a Dem who also wants amnesty. Plus, the immigration issue will be a moot point after an amnesty bill- the 12 million illegals will suddenly be legal guest workers. Illegal immigration won't be a very big issue for a decade or so. I probably won't vote at all if an amnesty bill passes.
"...12 million illegals will suddenly be legal guest workers..."
Hmmm, I wonder if that would help the baby-boomers social security base? Or, is Congress already thinking of ways to spend the money?
I think you answered your own question when you ended the paragraph. You're not the only one who'd stay home or (better yet) vote third-party. I think a lot of Republican politicians are acutely aware of that. It's just that more of them need to be made more aware of it.