> But research suggests that there is a neglected dimension of polarization, one driven by age: younger people are disproportionately liberal, and then drift steadily to the right, becoming just as disproportionately conservative by retirement age... “We can say, with a great deal of confidence, that people get more conservative when they get older—and a lot more,” says Chicago Booth’s Sam Peltzman, who conducted the research. “It’s not just a little bit. It’s a pretty big change over their lifetime.”

https://www.chicagobooth.edu/review/there-are-two-americas-a...

Your link says that at age 25, 33% are liberal, 25% conservative, and the rest moderate. "Overwhelmingly liberal" is hyperbole. "Lean liberal" is accurate.