If millions of registered republicans suddenly switched their registration to a third party it might sink in through the thick skulls of the stupid party. I switched to being registered LP the day Romney was nominated.
We could all switch back for primary votes, if there are any worth supporting. Colorado primaries are so far back we do not have a choice in the presidential primaries.
That will only make the GOP move to jettison the remaining conservatives (fiscal and social).
A third party takes decades to build. The GOP would love to be allowed to move left and merge with the “moderates” of the Dems.