Manchin represents West Virginia which, if you’ve never spent time there it is incredibly difficult to overstate how important the coal industry is to the state. And I used that phrase to refer to how culturally important it is, not how important it is economically. Coal as a mass employer of West Virginias was in step decline by the 1980s, and I think even 20 years ago it was no longer the single largest employer in the state (I think Wal-Mart and the State government employed more people than coal by then), but the effects of being a single resource economy for like 100 years take many decades to disappear.
For huge swathes of the state, there’s a legacy of “we’re here because of coal”, maybe not anyone in their immediate family works in coal, but maybe their grandfather did, and maybe they moved here from Italy before WWII to work in those coal mines. Coal was seen as the bedrock of the community, towns like Welch in McDowell County were happy and booming places in the 1960s, and are hell holes now. Coal has taken on an emotional and psychological element in the State. Most of the State firmly, and deeply believes with religious fervor that things are bad in the State because of the collapse of the coal industry. Various hills like the opioid epidemic, the exodus of young people (especially those with education or any job prospects) et al. are firmly blamed on the collapse of the coal industry. That belief has some truth to it, although like most things there’s more to it. But going hat in hand with that belief is a strong belief that the coal industry in WV didn’t die off for the reasons it actually died off–seams being mined out of profitable coal after 150 years, mass mechanization with the deployment of continuous mining machines that replace around 100 miners per machine, shifting electric generation to natural gas away from coal, the rise of coal development in other regions with newer seams that can be more profitably mined (and are thus more competitive)–instead the widely believed reasons is “Democrat environmentalists” killed coal, and with it all the communities who died along with coals death.
Manchin represents to his constituents that he’s one of them because of his unwavering defense of the coal industry and his broad rejection of most of the Democrats environmental policy–positions he’s held ever since he entered electoral politics 20+ years ago. Now does Manchin really believe this narrative? I think he probably believes some nuanced version of it, remember before politics Manchin made his money as coal broker, he’s not just taken money from the industry he was in the industry. He likely understands there were systemic issues to coal’s decline but he also likely genuinely feels that as a Senator from West Virginia, he’s not going to take votes for issues that are so oppositional to the religious beliefs of his constituency.
For many years Manchin has been one of the few prominent advocates of technology like “clean coal” and carbon sequestration etc. I don’t really think he’s pretending; I think if you’re steeped in West Virginia culture, being pro-coal is a cultural shibboleth. This is way bigger to him than political donations though, it’s much more about saying what you stand for, and in West Virginia you god damn better stand for coal.
Before the modern era, West Virginia Democrats could largely get by without such stark behavior because 1) West Virginia was an old school machine politics Democratic state dominated by unions, and the workers were voting for who the union said and didn’t deeply analyze their positions and 2) before the 2000s or so environmental policy wasn’t getting nearly the political attention it has since. For that reason, you had the long-term Senatorial team of Robert Byrd and John Rockefeller IV, both of whom were closer to their party on environmental issues than Manchin has been. I think there is no space for Democrats like that now in WV politics.