Or maybe they (D's) are just getting better at doing what they do and how to do it, and are starting to understand that a win (even with a slim margin) is still a win, and that a tight race that that has a bit of back and forth throughout the tallying is a lot easier for people to accept than an obviously skewed and/or implausible blowout.
In the end, even if it is all mostly legit, we are still being played in a game we are steadily losing the chances of winning. JMHO