MANCHESTER, NH - FEBRUARY 06:  Republican presidential candidates Jeb Bush (L) and Donald Trump talk following the Republican presidential debate at St. Anselm College February 6, 2016 in Manchester, New Hampshire. Sponsored by ABC News and the Independent Journal Review, this is the final televised debate before voters go to the polls for the New Hampshire primary on February 9.  (Photo by Joe Raedle/Getty Images)
MANCHESTER, NH - FEBRUARY 06:  Republican presidential candidates Jeb Bush (L) and Donald Trump talk following the Republican presidential debate at St. Anselm College February 6, 2016 in Manchester, New Hampshire. Sponsored by ABC News and the Independent Journal Review, this is the final televised debate before voters go to the polls for the New Hampshire primary on February 9.  (Photo by Joe Raedle/Getty Images)

    JUST WATCHED

    Donald Trump: Jeb Bush is 'a sad person'

MUST WATCH

Donald Trump: Jeb Bush is 'a sad person'

Speaking with CNN's Wolf Blitzer, Republican frontrunner Donald Trump responds to Jeb Bush calling him a "liar and a whiner" ahead of the New Hampshire primary.

Donald Trump: Jeb Bush is 'a sad person'

Speaking with CNN's Wolf Blitzer, Republican frontrunner Donald Trump responds to Jeb Bush calling him a "liar and a whiner" ahead of the New Hampshire primary.