Why are Tennessee's suburbs still vote Republican

[mileslunn]

Memphis still has a lot of racial polarization and not nearly as many people from out of state like Atlanta and Dallas metros do.  Nashville less so but collar counties are a mix of suburban and exurban.  City of Nashville covers entire county so includes many areas that would be suburbs in other states while in surrounding counties, areas near Nashville are competitive and are unlike rest of state trending leftward even if still voting GOP.  These counties include large rural part where GOP wins big.  In some ways they are like suburban counties of Indianapolis which also still vote GOP as include suburbs in areas bordering the Davidson and Marion counties but as you go further out more rural.