Reed is seeking a second four-year term in Tuesday's nonpartisan election.
A former state lawmaker, Reed is known for his strong support of President Barack Obama and his working relationship with Republican Gov. Nathan Deal on issues including economic development and transportation.
Reed hasn't been immune to criticism. Open government advocates have challenged Reed over a plan to use public financing to help support a new Atlanta Falcons stadium. Also, a group of street vendors have expressed unhappiness since the city took steps to curtail sales on public streets.
Polls will be open until 8 p.m. Tuesday.
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