The Democrats are finally giving up on trying to reach these people. Maybe Bernie has the patience, but many have thrown up our arms in frustration and desperation.
This is the part of the country that the GOP takes their vote for granted. These people have no idea what power they wield if one day they got together and sent a message to the GOP by crossing the political line in an election.
The mainstream Democratic party abandoned the people living in the rural South a long time ago. "They gave up trying to reach these people" decades ago. The mainstream Democratic party has ignored the issues that are on top of the concerns list of the people in poor rural counties; jobs, illegal immigration (taking the farm jobs), social conservatism, Christian values (used to be in the Democratic platform BTW), economic development grants, gun ownership, keeping rural military bases open, rural hospitals (notice they are all shutting down under ACA), transportation, federal farmland regulation overreach, and other rural issues.
The only item the Democrats support that help rural counties is welfare (Food stamps, Section 8, etc.) and the only reason the Democrats support this for rural counties is because it aligns with their national platform. Note that the bulk of welfare money goes to Democratic cities in the U.S. when looking at actual payments.
The Republican platform more closely addresses the concerns of rural counties. The Republicans oppose illegal immigration, make noise about creating jobs, are socially conservative, support economic development and transportation grants for rural areas, oppose farmland regulations, support gun ownership, support rural military bases, and are the only ones at state levels to keep rural hospitals open. However the Republicans oppose increasing welfare payments but the reality they do little to take away existing welfare.
After decades of ignoring the concerns of rural counties and writing them off; it is very unlikely Democrats can "take them back" unless the Democrats re-write their messaging and platform to address the concerns of rural residents.