FiveThirtyEight takes a dive into voter demographics, Religion And Education Explain The White Vote
Let’s start with the wrong answer: income. Despite the myth that Trump’s base is poor whites, income is the least predictive3 of white voter support among the seven demographic variables tracked by the poll.
Instead, the two most predictive variables are religious attendance and education. Crucially, these two variables are still more explanatory when considered together. Roughly speaking, a white voter will lean left if she is ‘more college than church’ and will lean right if she is ‘more church than college.’4"