I wouldn't say Democrat takes on libertarianism have ever been very good. Especially in recent years with the alt-right trying to occupy the middle space between "libertarian" and "Republican" and adding to the confusion.

You have a problem on two ends - corporate interests can get out of hand, pollute, monopolize, etc., and you want to rein that in somehow. This can be done via the market, since corps do need money to survive, but a lot of people don't care enough to make it happen. On the flip side, if you rely on government to just control everything and hope they'll act benevolently, there are huge risks - a government agency could be benign or beneficial, or it can turn into a machine for oppression and monopolization.

I feel like the Democrat takes never acknowledge the negatives of state control (at least unless it's something Republican-associated) and also never acknowledge there's a valid way to accomplish anything outside of the state. It seems like their answer is always to just throw state programs at everything. Well, we did try having the state run everything once...