This last debate's numbers can be interpreted in one of a couple of ways.
1. Keith Olberrmann - Consistently at the bottom (or near the bottom) of the daily cable news show ratings. There's a reason for his dismal performance, he represents the noise-making far-left wing of the Democratic Party and there aren't as many as they would have us believe.
2. Union membership is way down. This is why unions are targeting Wal-Mart. They are on the verge of becoming irrelevant and it's quite possible that the bulk of the American people don't care about them, as much as they once did. They are a part of the shrinking power base, therefore, their influence is diminishing.
If I am wrong about either of these reasons, the viewership will continue to be low in the next debate. If I am right, viewership will climb back up.