We’ve had progressive politics (even a Progressive Party, for time) in the US at least since the early 1900s. In a nutshell, it’s about building a better nation from the bottom up – legit aid for the ;poor at one end, firm restraints on corporate and financial powers on the other end. The Dem Party began leaning to the right with the Reagan Democrats of the 1980s. They moved even further to the right in the 1990s, merging with the Clinton “New Democrat Party.” They ended actual welfare aid, took the first steps to similarly “reform” Social Security (targeting the disabled), expanded the share of workers who can be paid even less than min. wage, signed on to NAFTA, etc. In other words, the Democratic Party embraced a solidly regressive (not progressive) agenda.
To date, I haven’t seen that this “Progressive Caucus” has anything more to do with actual progressive politics and ideology than Progressive Insurance, or for that matter, Progresso Soup.