This is not surprising - kind of like putting all the men in the US into the army, and then discovering half the army is below average in intelligence.
Naturally, if the GOP starts to be such a large majority it includes nearly everyone who is not a left-wing kook, this is going to start happening.
True. Almost all actual debate now takes place entirely within the Republican party. A lot of people don't realize that there really aren't enough conservatives to form a majority, if we could even agree on what being a conservative means. There's absolutely no debate or initiative inside the Democratic party, once you get past "Bushitler", "Cut and run in Iraq," "socialize medicine," and "legalize homosexual marriage," all of which have been soundly rejected by around 60-70% of the population. The attempted elimination of Joe Lieberman demonstrates that the Democrat core is so ideologically driven that there is no room for any debate within the party. Traditional liberals looked for a new home. They found it with the Republicans. Rudy Guliani is an excellent example. He is not ideologically pure enough to be a Rat, even though he favors tradional democrat positions about 70% of the time.