"Why were the Republicans unable to change things when they controlled the House, Senate, and Presidency for 4 years?"
Because enough Republicans are Rino's, that's why. Leftists come in many creeds, colors, cultures, religions and political labels. Another reason is that a lot of conservative R's just don't have the focus that leftists do, they like to think of themselves as being above the fray and that Americans will react to logic rather than emotion. That is a mistake. Emotion trumps logic all day long. Why do you think advertising is a multi billion dollar business?
Ben Franklin, iirc, said that they, the founders, gave us a Republic if we can keep it. I think it's slipping through our fingers because of apathy.
As for Obama, since being elected, he now knows all the facts. I think once he got that briefing he said those famous words....."Oh s***!".