This is the significant problem facing the GOP these last few years. There is no one inspirational left in the party for anyone to vote "for"; we're just voting "against" the other party. At least on a National level. Hasn't been since Palin herself. (And no one outside of FR knows of people like Ted Cruz to even be inspired by them)
A political party can't last like that. Something needs to change. Certainly every conservative in Kansas needs to vote for Roberts at this point but sheer momentum can only carry a political movement or party so far. Eventually the momentum will die off, if all there is to the GOP is the message, "Vote for us, at least we aren't Democrats"
That slogan will mean nothing in 5-10 years (assuming it means anything even today).