In the first place, honoring Martin Luther King Jr. with a day off school is like honoring Ghandi by slaughering and eating a cow while singing God Save The Queen.
In the second place, comparing a religious holiday like Christmas with secular holidays like Columbus Day or MKL Day is moronic, particularly when it comes from someone I credit with being more intelligent than that. The only people I've seen make that argument with a straight face are the people who argue that "Christians" are oppressed.
And finally - Christmas
IS one of the Federal holidays.
2005 Federal Holidays -
http://www.opm.gov/fedhol/2005.asp
Friday, December 31, 2004 * New Year's Day New Year's Day
Monday, January 17 Birthday of Martin Luther King, Jr. Martin Luther King
Monday, February 21 Washington's Birthday George Washington
Monday, May 30 Memorial Day Memorial Day - See Our Commemoration Page
Monday, July 4 Independence Day Independence Day
Monday, September 5 Labor Day Labor day
Monday, October 10 Columbus Day Christopher Columbus
Friday, November 11 Veterans Day Veterans Day
Thursday, November 24 Thanksgiving Day Thanksgiving Day
Monday, December 26 ** Christmas Day