He has done many good things including improving economy and image of America in the rest of world. But there are a group of far-right fanatically religous republicans backed by their Israeli lobbyists who want to undermine him. They have no better alternatives when it comes to his economic policies and other issues. The truth is they don't care about America. The only thing that matters to them is to turn America into a religous Christian Republic ruled by evangelists and also give more unconditional support to Israel regardless of crimes Israeli government are commiting.
U.S., allies conduct 31 air strikes in Syria and Iraq against ISIS militants (Reuters)
from the article: Poll: Obama's ranking in Muslim world slides over Mideast