Are 700,000 Americans on 'some watch list or another'?

(CNN)During a recent appearance on CNN's "State of the Union," Florida Sen. Marco Rubio said "there are 700,000 Americans on some watch list or another." Jake Tapper checks the claim as part of a partnership with FactCheck.org.

Sen. Marco Rubio vastly overstated the number of Americans on the federal government's various terrorist watch lists. He said there are "700,000 Americans on some watch list," but the number is actually in the tens of thousands.
Rubio, a Republican senator from Florida running for president, voted Dec. 3 against a Democratic-sponsored amendment that would have allowed the U.S. attorney general to use the consolidated terrorist watch list to deny a known or suspected terrorist from legally buying a weapon, if there is "a reasonable belief that the applicant may use a firearm in connection with terrorism."