In 1959 as a result of an advancement in the Constitution, 45 constituencies were provided for Jamaica, an increase of 13 constituencies over the 32 which had been fixed in 1944. This necessitated new maps and new descriptions for all the new constituencies. Clarendon South Eastern was among the 13 newly-created constituencies.
Of the 10 contested parliamentary general elections from 1959 to 2011, the Jamaica Labour Party (JLP) won eight compared to two for the People’s National Party (PNP). Clarendon South Eastern which evolved from the former constituency of Clarendon Southern has a unique history, in that it produced two Prime Ministers – Sir Alexander Bustamante (1962-1967), and Rt Hon Hugh Shearer (1967-1972). In 1959 and 1962 “JLP river overflowed its banks,” as Bustamante overwhelmed his PNP opponents with landslide victories. When Bustamante retired in 1967, the mantle fell on Shearer to contest the newly-created Clarendon Southern seat which he won by a 2,925 majority. In the 1972 general election, the incumbent Prime Minister retained his seat in a close contest by polling 5,136 votes to 4,793 for Amador Gilman (PNP), a majority of 343.
In the 1976 Constituencies (Boundaries) realignment, Clarendon Southern was removed from the parish and Clarendon South Eastern restored. Shearer defeated Ronald Powell (PNP), by 2,134 votes. Four years later, Shearer polled 9,712 votes to defeat Churchill Henry (PNP), who polled 3,178 votes. There was a dramatic turnaround in 1989 when Shearer polled 7,299 votes to 7,295 for Emanuel Cousins (PNP), an unprecedented majority of four. The writing was clearly on the wall as in 1993, the master trade unionist, former Prime Minister and veteran politician lost the seat to Peter Bunting of the PNP. The JLP got 5,215 votes and the PNP, 6,658 – a majority of 1,443. In 1997, JLP candidate Edwin Singh polled 7,242 votes but was defeated by Basil Burrell (PNP), who polled 7,296.
The JLP turned the table on the PNP in the 2002 general election, as Rudyard Spencer polled 7,997 to defeat Burrell (7,425). St Andrade Sinclair of the National Democratic Movement/New Jamaica Alliance (NDM/NJA) polled 53. He has retained the seat since then, winning the 2011 contest 8,843 to 8,736 over Dereck Lambert (PNP).