the stupidity of "politically correct"

I saw an absolutely amazing post about the utterly idiotic extremes politically correctness has been taken to, and I saw it here.

To quote a relevant piece:

Valerie Jarrett is a well-known liberal figure with a history of vocal support for LGBT causes. Jonathan Capehart is a respected openly gay journalist who helped moderate the first presidential forum on gay issues for the LOGO network and the Human Rights Campaign in 2007. Juan Williams was NPR’s sole black, male commentator, with a distinguished career spent chronicling the civil-rights movement, addressing minority issues sensitively and sometimes bravely.

If, despite their obvious good intentions, none of these three could be given the benefit of the doubt when it comes to discussing sensitive social issues, exactly who can have these discussions without being deemed a bigot?