The Dems will be unable to recover many of these lost voters, because there was a significant percentage of Southern whites who voted Dem simply because their family "always voted Democrat", and had done so for generations. The Dems went SO far Left this time, that even these eyes-tightly-shut legacy voters finally had to admit to themselves that the Democrat party was no longer "their father's Democrat party". With the veil lifted, the Dems will not recover these voters without shifting positions on nearly every racial issue, gun issue, and religious issue, which they will never do. (They may promise to do so, and it may work for one election, but it would never work a second time. Southerners are not known for quick forgiveness on major issues they hold dear.)
The party started moving to the right in the early '70's, with Goldwater as an inspiration. The rats pushed a little to far and it bit them.
I think that when the final rino purge takes place we are going to have about three generations of Conservative government.