Why are some people so paranoid and petrified by Obama ?

Fear-mongering. It has worked before, and is working again. Find a way to scare somebody and act like you are the solution, and they will do anything you tell them. The outrageous claims of Obama being linked to Bill Ayers, is just another play on peoples fears. Or calling him a Muslim. They all serve the purpose of scaring, and making it easier herd people. Keep the population afraid and demoralized and you can control them easier.