I have given thought that if Trump does continue to sink in the polls, that the RNC focus all funds on those close Senate races. A GOP senate may be the only prevention we have from a Socialist Tsunami.
I agree. The Dems appear ready, if they retake the Senate, to abolish the filibuster and with it the power of the minority to stand athwart the socialist tsunami. With the Senate, the GOP can play effective defense and stop the most radical stuff, including the most radical judges.
To me, this must be the eye-single focus going forward. Voters who dislike Trump must be persuaded to nevertheless split their tickets.