sentences:  Thatcher's political "assassination" was, according to witnesses such as Alan Clark, one of the most dramatic episodes in British political history.The idea of a long-serving Prime Minister—undefeated at the polls—being ousted by an internal party ballot might at first sight seem bizarre.However, by 1990, opposition to Thatcher's policies on local government taxation, her Government's perceived mishandling of the economy (in particular the high interest rates of 15% that eroded her support among home owners and business people), and the divisions opening in the Conservative Party over European integration made her seem increasingly politically vulnerable and her party increasingly divided.