The Pew study also looked at social and political views, not just religious ideals and practices. Here’s how the Unitarian-Universalists answered:
10% of UUs are Republican in political orientation
77% of UUs are Democratic in political orientation
9% of UUs are political conservatives
32% of UUs are political moderates
51% of UUs are political liberals
96% of UUs believe homosexuality should be accepted, surpassed only by Reform Jews (98%)
81% of UUs believe abortion should be legal in all or most cases
80% of UUs believe that stricter environmental laws and regulations are worth the costs to the economy
80% of UUs worry that government is getting too involved in morality issues
I didn’t dig too deep, but from the sample sizes, I don’t see how they can draw and conclusions about UUs.