And...?
The show did eventually take on its usual fairly heavy anti-Republican stance, but even before then it was a pretty bad attempt at satire. Like, the characters were just totally flat. It didn't feel authentic at all; just a really hollow spoof of the current presidential race. To me, this whole episode felt like a series of interstitials for a Fox 2008 Election Special that would be combined as a "bonus episode" on the DVDs, rather than an actual episode. It just didn't go anywhere.
By the way, if you're looking for a Simpsons jab at Democrats, you'll have to look back to season 3's "Black Widower", when Sideshow Bob says "You can't keep the Democrats out of the white house forever; and then, I'll be back on the streets, with all my criminal buddies! Ha ha ha ha ha!"