Universal health care is antithetical to both market economies and economic freedom which are both core liberal principles. Liberals cannot actively support it without also confronting the inherent contradictions within liberal ideology.
Unless you're using the term "liberal" in the US sense of 'anybody "left" of fascism' in which case you're statistically correct, but mostly due to generalization.
Since Nixon vs. Humphrey vs. Wallace back in 1968.
In 2024 pproximately 59.0% of voting age population voted, which is 63.9% of voting eligible population.
2020 was the only year to surpass with 62.8% VAP/65.3% VEP.
3rd place is 2008 with 58.3% 61.6%.