Even with a Democratic majority in Congress, President Barack Obama may face some political struggles as some Democrats, namely Nancy Pelosi and Harry Reid, have said that they will not necessarily go with everything the President says. Specifically, Pelosi wants tax hikes on the $250k+ bracket immediately, whereas the President has said he wants to withhold the hikes due to the current recession.
source: http://www.cnn.com/2009/POLITICS/01/22/president.tension/index.html
source: http://www.cnn.com/2009/POLITICS/01/22/president.tension/index.html