WASHINGTON – By most measures, the southern state of Tennessee would appear to be a significant challenge for any Democrat in the upcoming 2018 U.S. Senate race. The governor, both houses of Tennessee’s state legislature, and the two U.S. Senators are all in Republican hands. Donald Trump defeated Hillary Clinton by a 26% margin in last year’s election. Nonetheless, with incumbent Senator Bob Corker announcing his retirement last month — the chances for any new candidate slightly rose.