I agree with your first two paragraphs.

To the extent that our present time is at all unique, I subscribe to Robert Putnam's thesis that much of what we see today can be explained by the drop in social capital in American life over the past several decades. Less socialization means less trust in other Americans or in the government, fewer norms of reciprocity and trustworthiness, and increased polarization. There are various reasons for this, television being a prominent example. Surprisingly, it seems as though these trends were firmly in place well before the internet or 24 hour news came along.