Yes, most of us are aware of that fact. What you should be asking is why, starting in the mid-60’s, did Whites desert the Democratic party in droves? What might have happened around then to cause such an exodus?
Further, one could ask “Why is it that so many Whites believe that because Grandpappy made a good living making buggy whips, and my Daddy made a good living making buggy whips, it is therefore both my right and my entitlement to make a good living making buggy whips?” Everyone else understands that the economy and workplace have undergone major shifts over the last 60 years, and especially over the last 100. But this fact has apparently has escaped many Whites, or else they realize it but don’t like it, and so they keep trying to reverse things back to they way they were when Grandpappy was making buggy whips and had a comfortable life.
These are much more interesting topics than simply pointing out obvious things like “White people don’t vote democratic”, which is itself really odd since as a whole, Whites do much better under Democratic leadership than under Conservative leadership.