It's easy to point to Supreme Court rulings, especially on gun rights and money-as-speech, that show policy moving to the right; DW Nominate scores, which are an objective measure, clearly show that Republicans have moved to the right without any Democratic movement in any direction. It's easy to cherrypick to show that the country is moving left or right (gay rights is a very easy issue to argue left with), but I don't think there's a clear pattern of movement in any direction (I guess you could argue left socially, but right economically, but that might be my own bias sneaking through).
The Democrats held both chambers of Congress from 1981-1995: are you going to argue the country wasn't moving to the right during that time? 
Democrats did not control the Senate from 1981-1987, but regardless, at that time, the Democratic party had a large conservative faction, and right-wing Republican Presidents were able to push their agendas through. Congress has been, partially since 2010 and totally since 2014, controlled by the opposition to the Obama Presidency, in a way that Reagan never experienced.
