I suggest you go to places like Lousiana and the Texas coast and count the towns who’s core industry is drilling and refining petroleum. Many Midwest and Southern towns only exist because of coal mining. Industries like petroleum and coal provide high paying jobs that end up generating whole service industry economies.
There is NO manufacturing industry in the world that employs a “lot of people”. That’s hardly a reason to force them to be done overseas when they can be done just as well here.
If you think people care more about vague “national security issues” than “where will I or my kids get a job” then you and I live around vastly different people.
I'm not saying energy industry jobs are not important. There's no reason not to push that angle in areas where the energy industry predominates. I'm just saying it's not the overall magic bullet for the GOP. The GOP really needs to make the case that cheap energy is important to the overall economy and improves everyone's economic well-being. And that the Democrat Party is standing in the way.