The former Missouri Democratic senator also explained why the former president is the "worst loser" America has ever seen.

Claire McCaskill has become the first lawmaker ... Sign up Some observers are taking McCaskill's move at face value, suggesting she simply wants to give Clinton an early boost in what is certain ...

Missouri Sen. Claire McCaskill is about to end the suspense on the biggest political question of 2015: Will she be running for governor in 2016 — or not? McCaskill, a Democrat, will make the ann ...