The Obama administration was pro-solar, so the GOP had to be, has been, anti-solar. Remember the Solyndra "scandal." It's not about "annoying the environmentalists" per see, it's about motivating those voters who do get revved up about annoying the environmentalists.

That's certainly not the only reason but it would be naïve to wave it away at this point. As the article points out, the situation we find ourselves in has been years in the making. US PV production has actually been in decline just as PV is starting to make sense.