The evolution of my perception of Obama has been very gradual. I voted for him in 2008 enthusiastically. It was the first presidential election I voted in and I believed that he would accomplish a lot even if it took a while and even if he didn't accomplish everything. Throughout his first term, I started to see things that raised red flags with me - things like not pushing harder for UHC and appointing Arne Duncan as Secretary of Education. Both actions in addition to others rubbed me the wrong way, but I let them go with the understanding that he was doing his best and perhaps misguided on some issues.
As time went on, I started to become even more disappointed with his performance, but before completely dismissing him as many of my liberal friends did, I decided that I would at least see what he did in his second term. Perhaps, I said to them and myself, he knows that he can't do certain things until the second term because he would be up for reelection. Perhaps, he just didn't have enough time the first go around. Then, the second term came around and he was pulling the same stuff.
He appointed a man who had never been in the FBI as the head of the FBI - an absurd move. He did a lot of other problematic things and then the NSA scandal broke. When that happened, I was extremely disappointed in the government in general although not surprised. However, what really disappointed me was how Obama responded to criticism of the programs. He was dismissive, arrogant and disrespectful to his critics including me and millions of others who voted for him. At that point, I was completely disillusioned. While I still believe he has done positive things - including, most recently, making the speech he did about race in America, I'm mostly disappointed. I don't subscribe to all the criticisms conservatives have about them, especially the hyperbolic and trivial ones. Instead, I'm disappointed that he didn't live up to the liberal principles I believe in. He's a fraud.