Whatever else he was, at least Dubya was an adult.
I believe the American people recognized that. However we are an adolescent people and don't like having adult s in charge. Hence, we picked the boy president the next time around.
But we know better, even if we don't act better. Consider Bush and the Patriot Act. There is much that is wrong with the Patriot Act but, aside from the diehards on the Left (and some of us on the Right who were/are deeply concerned about where it is taking us) people generally accepted some of the trade off. That was due, I think, to a begrudging respect for George Bush. You really knew that he signed on to it out of a desire to protect the American people.
Now we have the NSA and IRS scandals (among multiple others). Why are those things hurting Obama's ratings? Because even the adolescents of the country are suspicious of Obama's motives. They know he is not the adult that Bush is and they know that Obama is in it for the power and for the "fundamental transformation." Actual protection of the American people is way down on his list of priorities.
Americans are not stupid. They are foolish and they are woefully under-informed (thanks LSM), but they are not stupid.