Let me explain the joke for you: liberals are less likely to believe that verifiable facts and theories are merely contingent political preferences.
> There are two distinct ways to be politically moderate: on purpose and by accident. Intentional moderates are trimmers, deliberately choosing a position mid-way between the extremes of right and left. Accidental moderates end up in the middle, on average, because they make up their own minds about each question, and the far right and far left are roughly equally wrong.
Both sides just pick and trumpet the hard truths that they like.