President Obama has had a tough year. He failed to pass gun legislation. Plans for an immigration overhaul have stalled in the House. He barely escaped what would have been a humiliating rejection by Congress on his plan to strike Syria.
Just this week, his own Democrats forced Larry Summers, the president's first choice to head the Federal Reserve, to withdraw.
Former Clinton White House aide Bill Galston says all these issues have weakened the unity of the president's coalition.