Most people don't vote on platform. Most people are not party over country as you are. Most people vote on who they like the best. Most people didn't like John McCain... me included.
Until and shortly after 9/11, George Bush was loved by Americans. Even many liberals were giving him a shot. It wasn't until after 9/11 that the hounds came out.
President Obama is by no means the middle. He is simply an individual that many, many, many people happen to like including me. He is very charismatic. He is not in the Center.
And for your information since you seem to think that only conservatives are Republicans and only liberals are Democrats both parties have wide ranges in their political spectrums. Sure, maybe Democrats are farther left than the farthest Republican, and vice versa, but you cannot lump people they way you do.
And once again, for the 1012th time, I am not a Republican.
Immie