THE RISE AND FALL OF SPEAKER PELOSI

THERE'S ONE GOOD THING I'VE NOTICED ABOUT CRITICIZING PELOSI - VERSUS CRITICIZING OBAMA:

WHEN YOU ATTACK ANYTHING PELOSI YOU'RE NEVER ACCUSED OF BEING A SEXIST, BUT IF YOU ATTACK OBAMA, THEN YOU'RE ACCUSED OF BEING A RACIST.

WHY IS THAT?