The self-satisfied Democrats are large part of problem says US commentatorWatch this thread
But yes, the Democrats have never really been the party of workers or progressives. As Thomas Ferguson's 'Investment Theory of Party Competition' pointed out years ago, they are primarily the party of capital intensive industries, which are generally multinational and either employ relatively few workers at all (relative to the size of the business), or primarily employ overseas labour. By contrast, the Republicans are primarily the party of labour-intensive industries - not small businesses as such, but generally mostly or wholly US-focused, and unable to simply outsource their work to workers in foreign countries. Hence the Democrats are generally more favourable to immigrants and organised labour because their business backers have no obvious conflict with these groups, while Republican backers do.
In recent years, though, the Democrats have increasingly become essentially a non-party. While the Republican Party has become more and more ideological since the 1980s, the Democrats have more and more become the bland, non-ideological party whose primary selling point is not being the GOP. It is less a party and more an electoral machine that exists to produce and elect generic politicians (the GOP also used to do this, but it seems the Tea Party finally succeeded in getting the lunatics to take over the asylum).