premise: Margaret Thatcher was a president.
hypothesis: Margaret Hilda Thatcher , Baroness Thatcher , ( ; 13 October 1925 -- 8 April 2013 ) was a British stateswoman , who served as Prime Minister of the United Kingdom from 1979 to 1990 and as Leader of the Conservative Party from 1975 to 1990 . She became Prime Minister after winning the 1979 general election . Thatcher 's popularity during her first years in office waned amid recession and high unemployment , until victory in the 1982 Falklands War and the recovering economy brought a resurgence of support , resulting in her decisive re-election in 1983 .