Alabama's 21st Senate district is one of 35 districts in the Alabama Senate. The district has been represented by Gerald Allen since 2010.
Following Reynolds v. Sims in 1964, which ruled that electoral districts of state legislatures must be roughly equal in population, the Alabama Senate was reapportioned to elect 35 Senators from 26 districts. District 21 became a multi-member district, comprising Montgomery County and electing 2 Senators in 2 different contests. Following a further court case in 1972, the district, along with all others in the Alabama Senate, was reapportioned to a single-member district for the 1974 election.
Senators take office at midnight on the day of their election.
As a multi-member district:
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