Taxes. Since 1980, they have lowered taxes to ridiculous extremes. Deregulation of businesses. Doing everything to give large businesses, CEOs and large shareholders free reign, while undermining the middle class. Income of the middle class has been pretty much stagnant since about 1980, while incomes of the top 1% has gone through the roof since then. Wealth inequality has gone way up.

I recently read that in 1970, Republicans still supported Basic Income.

This is a comments section. If you want citations, read articles. It's impolite to demand someone here be held to that standard. We know from context that these are opinions, and everyone has the opportunity to provide citations if they want to, but don't demand them.