Democrats, both among elected officials and registered voters.
The so-called "moderate Republican" is near-extinct. They've either left the party, or continue to self-identify as a moderate despite becoming increasingly radicalized along with the rest of the GOP.
It's more so that the current "centrists" in the GOP are a bygone era's extremists. The party has moved so far right that Ken Buck now looks reasonable compared to an Andy Biggs, for instance. The right wing spectrum has moved so far right that what used to be considered far right is now closer to the center.
Basically, Republicans who have broken clock moments are rare "centrists" compared to the standard of the majority of the party being clocks with no hands whatsoever.
Poll
