Kennedy is the most popular officeholder in Louisiana, the fact that he’s only ahead by 4 in this poll (which is actually part of a downward trend, since Kennedy was up by more than that in previous polls) and decided against a run tells you all you need to know about this race. A competent Republican could make this interesting, but "polarization" alone isn’t going to spell doom for JBE, especially since 2019 will be a far more D-friendly environment than 2015. Lean D without Kennedy. Gun to my head, Democrats win MS and LA while Republicans hold KY by an underwhelming margin.
KY, LA or MS aren't assued to the GOP