Since the map is so large I'm going to put the link to the wikipedia article about the 2016 presidential election in TN. If you look at the map at the right in the article, you'll see some of our counties are turning pink instead of being deep red. Knox County is the pale pink towards the upper right. It went 58.53% Trump/34.80% Clinton so not terrible, but the next largest county in East TN, Sullivan, was 75.43% Trump/20.20% Clinton. https://en.wikipedia.org/wiki/2016_United_States_presidential_election_in_Tennessee
And I would agree with your mom, that there's lots of liberals moving in because the Knoxville area has been ranked as one of the best retirement areas and best places to raise a family for several years.
I live in one of the paler pink areas. Our results were about the same as Knox County, and we're a military town! I'm born and raised Tennessean but that's why I'm considering a move. Have a few years to decide though.
Thanks for the infos. Troubling. She says she sees CA plates all the time.