Mike Espy, a former Democratic congressman who served as Secretary of Agriculture during the Clinton administration, announced Friday that he would run for the U.S. Senate in Mississippi.

Espy is running for the seat recently vacated by Republican Sen. Thad Cochran, who resigned earlier this month do to health issues. The state's Republican governor, Phil Bryant, has appointed state Agriculture Commissioner Cindy Hyde-Smith to replace him. A special election for the seat will be held on November 4th.

Mississippi is typically safe Republican terrain. But Democrats are hoping that Espy, a well-known moderate, can pull off an upset. The special election will be non-partisan, meaning that no party identification will be present on the ballot. Should no candidate receive 50 percent of the vote, the top two finishers will compete in a run-off election.

Hyde-Smith is running in the special election, which is also being contested by Republican state Sen. Chris McDaniel, who came close to defeating Cochran in a 2014 Republican primary. Tupelo Mayor Jason Shelton, a conservative Democrat, is also running.

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Should he be elected, Espy would be the first African American to represent Mississippi in the U.S. Senate since Reconstruction. If he can unite Democrats behind him and generate large black turnout, political observers believe that he could advance to and then potentially win a run off, particularly if he finds himself in a battle with McDaniel, who is thought of as a divisive figure.