Why is it acceptable now for people to insult President Obama, when it was unacceptable with former President Bush?

I did come in at the tail end of President Bush's presidency, so perhaps it's perspective , but even in civilian life it came across as "treasonous" to insult, mock or in question the loyalty of the current President.

Since President Obama has taken office, I'm heard blatant insults, remarks on his religion and national origins and blatant statements now about his loyalty, even in this community.

Edit: I'm not discounting that President Bush was insulted. I fully acknowledge that he was. This is also wrong in my opinion. Why was that tolerated previously, why is insulting our current President tolerated now?

Edit 2 : For those that just come on for an easy way of saying "This political party is the reason for all of x, y and z", I'm basically going to ignore you. It's not the point of the conversation and you add nothing to the conversation.