While I am a big fan of how Scandinavian countries run things, I would imagine that it's much more difficult for a country like the U.S. to transition from very right wing economic policies to left wing ideals. Like the article says, many of these new government program would be expensive and necessitate higher taxes, something that will be felt by the population immediately, yet the payoff (i.e. improved public services) will take time to put in place and provide the aimed benefits of higher taxation. I think making such a shift from the left to the right means that things will always have ot get worse before they get better - I don't think voters will have the patience or foresight to elect (and certainly not re-elect) a president who would put such a plan in place.
I think this is why many left wing ideals are borne out of times of crisis, when everything collapses and you need to rebuild from the ground up. Think the formation of the HSE after WWII, or for a much more modern example Iceland shifting dramatically to the left after the crash in 2008. It seems easier to build a left wing government in this way.