President Obama apparently received a loud chorus of boos when he appeared on the big video screen for a brief time to commemorate Fenway's 100th anniversary. Unfortunately, no one seems to have the video since it was before the game.
Keep in mind - this isn't the South - it's the heart of liberalism. Granted, there are probably a lot more males than females, and he is not well liked by males. But still - it takes a lot to get booed so badly in Boston. Apparently the other videos (from Conan, Mark Wahlberg, Dennis Leary) were well received.