Final answer:
Bill Clinton was not a presidential candidate in the year 2000 because he had already served two terms as President and was ineligible for a third. The Democratic nominee was Al Gore, and George W. Bush was the Republican nominee.
Step-by-step explanation:
Among the options provided, Clinton was NOT a presidential candidate in the year 2000. During that election cycle, the Democratic nomination was won by Clinton's vice president, Al Gore, who then competed against the Republican nominee, George W. Bush. Bill Clinton, having served two terms as President of the United States, was ineligible to run for a third term. The other candidates mentioned, Bradley, Keyes, and McCain, were indeed participants in the 2000 election, with Bradley running as a Democrat, Keyes as a Republican, and McCain also being a prominent candidate in the Republican primaries.