Voting for GOP candidates isn't going to change anything.
But that will probably never happen, because forming and operating a political party is too much like joining a union with its own PAC. And also, third parties don't count for much in the US.
Its playing the two sides off each other that might work. Make the GOP think will vote for them. Make the democrats think they'll loose our contributions.
Getting rid of Feinstein will be an excellent first step.