This is a big problem in ALL political polls. Republicans almost unanimously choose the options they think will be worst for Democrats. This weights ALL polls against Democrats, and I suspect that weighting schemes magnify the effect.
Do Republicans actually believe their responses? We don't know.
Reasonably clear they don't in many cases — economics as an example, they're proud of their own personal economic situation, their neighbors, and even their if red, state. But...not the U.S.