Since the reagan years the repubs have used the slow witted, simple talkin' type of politicians to appeal to your average Joe American laboror mentality. That down to earth regular guy type image is used to appeal to the least educated most impressionable sector of the public.
At the same time repub economic policy looks after the well to do to rich, and big business and keeps them where they are.
It's a balance of the powerful to back them and the brainwashed average Joe American to vote them into office.
On top of that coming in after the failure that Carter was as a president, Reagan was able to swing the country to the conservative side and make liberal a dirty word again.
Bush1 was able to ride that out his first term but then lost because of the economy.
Clinton came in and liberal started looking not so bad, a president that admitted he had smoked dope and nobody really cared. But unfortunately after all those years of relentless repub persecution they finally caught Clinton in a lie about his sex life and he lost his credibility. Despite the public's disappointment Al Gore still barely lost the election based on very questionable results in Florida, but in the end bush2 got the win.
Then 9-11 happened, the public was shocked, scared. A sense of insecurity blew across the nation.
Now with the already impressionable section of the public now scared as well the climate was perfect for a slow witted, simple talkin' president to win them over. This is what makes it possible see current situations like bush2 continuing to insist on and al queda/Iraq connection while the evidence coming out all around him says that's not so, however a large piece of the public continues to buy it.
In short those that refuse to think and are running on blind faith are why bush2 is favored in the odds.