West Virginia has a Democrat governor.
Trump is playing a long game of chess, while the Democrats are pursuing Tiddlywinks. And missing the cup just about every time.
I'm pretty sure that the Democrats, Heitkamp and Machin in particular, are well aware of the fact that the only reason they're under consideration is that they are Democrat senators. And they also have to know that they have a better chance of re-election in 2018 than still being in the cabinet in 2018.
Manchin may not be an “automatic” return to the Senate. My WV relatives tell me his “schtick” is wearing thin with the boys & girls in those hills.