Boston, Massachusetts (CNN) -- In a stunning upset that reshaped the U.S. political landscape, Republican Scott Brown won Tuesday's special election in Massachusetts for the U.S. Senate seat formerly held by liberal Democrat Ted Kennedy. Brown defeated Democrat Martha Coakley, the state attorney general. Brown's victory made real the once unthinkable prospect of a Republican filling the seat held by Kennedy, known as the liberal lion, for almost 47 years until his death due to brain cancer last August. Before Kennedy won the seat for the first time in 1962, his older brother John held it for nearly eight years until his election as U.S. president in 1960.
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Republican Scott Brown upsets Martha Coakley to fill Ted Kennedy's seat
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Win leaves Democrats without crucial 60th Senate vote needed for health care overhaul
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Brown's platform includes backing tax cuts, being tough on terrorists
No Republican had won a U.S. Senate race in Massachusetts since 1972, and @placeholder control the governorship, both houses of the state legislature, and the state's entire congressional delegation.
In a sign of the high stakes involved, the @placeholder campaign held an afternoon news conference Tuesday to complain that voters in three places received ballots already marked for Brown.