and also, joe lieberman's life in the senate and american politics is also kind of a microcosm of regional and ideological changes within the democratic party. so he arrives in washington 1989 as a quiet centrist democrat, replacing a brash liberal republican, lowell weicker. he is an early advocate of bill clinton, and he's a strong supporter of the clinton administration's policies but he breaks with bill clinton memorably over monica lewinsky and the extramarital affair there. he doesn't vote to impeach -- >> norah: but he rebukes him -- >> reporter: but he rebukes him, and that stings. he also gets the attention of al gore, becomes his running mate in 2000. but as he continues his political career, he becomes more and more estranged from the democrat party. an advocate, a fierce advocate of the iraq war. 2003 he runs for president. 2004, progressive democrats give him no traction whatsoever. in 2006, he's defeated for reelection by a democrat runs as an independent and wins. but in 2007 -- december of 2007, he endorses john mccain. completing his estrangement from the democratic party.