If you want to talk alienating people there's clear differences between the two parties as well. Let's assume you're correct that Democrats are alienating coal miners and basically anyone else that makes their living from fossil fuels. Who are the Republicans alienating?
- Immigrants. Particularly ones that aren't white and Christian (both combined; if you're not white but Christian they don't want you).
- Various minorities such as blacks and Latinos but especially LGBTQ people (and 1000x if they're trans).
- Scientists, professors, and basically everyone involved in accredited colleges (non-accredited fake schools like Liberty University are welcomed).
- Health care workers (but not private hospital owners). Especially doctors and nurses working in gynecology, labor & delivery, and anyone working in transgender treatment.
- Anyone in a union and unions in general (but this has always been the case).
The Republican argument has always been that even though they (obviously) hate or at least don't give a shit about all these classes of people their (non-existent) economic policies will benefit them somehow. Economic studies as well as basic measures of social health have all shown repeatedly that this is untrue. The actual (partisan) laws enacted by Republican majority in each state as well as federally have had negative impacts both economically and on the general well-being being of their constituents.
For incredibly obvious examples, the Texas Republican legislature banned municipalities from instituting mandatory water breaks for workers. Georgia's banned handing out water bottles to people waiting to vote. Florida is banning books with any sort of sexual theme (including biology books and books on sex education!) and the mere discussion of anything related to LGBTQ topics in schools.
In what universe are these good policies? They're not. From an economics standpoint Republicans are the kings of unnecessary licensing requirements (aka "job killing regulations") and placing unnecessary restrictions on job seekers as well as welfare programs in the form of mandatory drug testing (which has no purpose; do we really care if some disabled veteran is doing drugs from time to time?), extremely flawed citizenship checks (because there's no national database regular citizens are being denied), and banning necessary medical care (abortion, which is a human right according to the UN).