When Americans are surveyed, far more claim to be conservative than liberal. Conservatism is relatively politically inactive by definition. So among voters, about equal numbers are conservative and liberal because of the large numbers of conservative people that aren't interested in voting. So the government always has been and always will be more liberal ("activist"/"progressive") than the population.
You might be arguing about the US having a liberal government (true) vs. a conservative populace (also true) in general.
In years like this when legislation swings way over to the left and 3 trillion is added to the debt for a negative benefit, it brings out a slightly more accurate representation of the people's wishes in the election, because a larger overall percentage of voters will get off their butts.