Within a Mormon community, I would wager we would still see that the most educated Mormons are also, ON AVERAGE, the most liberal/leftist Mormons.
You're welcome to check. But we can see very definitively that a higher-than-average rate of education does nothing to increase the partisan character of the voting block.
we already know what the data looks like when we count everyone
We know that we have an overall liberal voting demographic that is unevenly distributed across the country.
But we also know that age, industry, ethnicity/culture, and region play bigger factors in your voting habits than degree of education. We can even see shifts in voting trends over time within the same voter cohort. The trend you're looking for is temporary at best, and highly contingent on the state, the school, and the field of study.
When you take broad averages like this, you very often lose useful information. In this case, just being "educated" in the abstract carries a weak correlation to political beliefs.