1984, not 1980, FWIW, and the Democratic Party old guard had been pretty badly beaten up by the 1968 and 1972 conventions. Tip O'Neill was one of the last of that group to really hold power.
[edit] I mean yes 1984's map was even worse, but 1980's was reeeeeal bad. Six states won in 1980, versus one in 1984. And we have a guy who won a pretty ordinary split of states and less than a majority of votes-cast calling his win in 2024 a "landslide", lol. No, Reagan's elections are what a landslide looks like.
[edit edit] I mean I don't really want to quibble over the details, it probably was the one-two punch of those that really set the direction and we seem to agree on the basics that it was Reagan's crushing electoral success that set the tone for Democrats for up until... well, still today, largely.