It’s possible, but perhaps not most likely. It’s useful to keep in mind how Real Clear Politics do their maths. They take most (if not all) the polls and calculate an average. That’s were they get the color of the state/districts. Very few of the polls systematically and habitually skew to the Republicans, but several do exactly that for the Democrats. That’s why these averages aren’t worth much, except as a marker of the trends. The measure of enthusiasm demonstrated by primary elections are at odds with the story that the media is telling. Both cannot be right.
Theoretically their process should work well, as they take a “poll of polls” which should theoretically eliminate outliers in the polling.
But if they are determined to show that Democrats are poised to do very well in the elections, people can twist the data to show that too.