The GOP gets back to its centre-right roots and boots out the Trumpists and Taliban-gelicals, which in turn will bring DuPage, Lake, and the northwestern Cook suburbs home.
That's not going to happen, sadly. Trumpism is the future of the GOP.
If the GOP loses bigly in 2018 and 2020, no it won't.
I honestly don't know for sure (I don't see how anyone can be certain about these things), but Trump wasn't just some Republican nominee who disappeared after the election. He actually won the presidency, and I'm guessing that his stamp on the GOP will linger for awhile.