It is true that President Obama began his first term with a feeling of hope and the sense that anything was possible. Over time, he has not kept all his promises and he has gotten quite negative about any possibilities. However, it is understandable given the Republican party deciding to blockade any action he might favor and the nasty tenor of politics in DC today.
Yes, the President's camp has become far more negative over time, because Obama had to realize that the job was not as easy as he thought it was going to be. Obama thought that he would be a dictator. He thought that he would be able to just speak and that other people would have to do what he said. When he found out it doesn't work like that, he became negative.
I thinkt he President's camp has grown more of a backbone and has stood up to republicans more lately--as they should have been doing for years now. This may sound negative to some, but it isn't. It's important that the President and his advisors stand up to the GOP in every way.
I do not believe the President's camp has become more negative over time. Obama's administration has hit many roadblocks and implemented many policies that simply didn't pan out the way they had hoped. Despite these downfalls, I feel the administration has remained positive and head strong, especially consider the amount of opposition it has faced.
The supporters of our President have not become far more negative, rather it is the Republicans that are very scattered at this point in time. The Republican party has began to degrade recently hurting all of the country. Their negative views just to try to get a few conservative votes is what you must be thinking of.