The Mississippi Senate runoff election ends as one of the most closely watched races of 2018

REUTERS/Jonathan Bachman (L) and REUTERS/Jonathan Ernst/File Photos

U.S. Senate candidate Mike Espy and U.S. Senator Cindy Hyde-Smith (R) are seen in combination file photos, in Jackson, Mississippi, U.S. on May 8, 2018 and in Southaven, Mississippi, U.S. on October 2, 2018 respectively.

• Voters in Mississippi have cast ballots in a hotly contested runoff election for a Senate seat in the state on Tuesday.
• The Mississippi runoff is the last Senate election to be decided since the November 6 midterm elections.
• The stakes are high. If Espy, a former congressman and Clinton administration alum, comes out ahead, he would become Mississippi's first elected Democratic senator since 1972.
• Hyde-Smith, the incumbent who was appointed to the office in March after Sen. Thad Cochran resigned, is favored to hold the seat in deep-red Mississippi. She also enjoys the support of President Donald Trump, who received nearly 58% of the vote there in 2016.

Mississippi voters have cast their ballots in the state's Senate runoff election on Tuesday, bringing to an end the final Senate election of the 2018 season.

Republican incumbent Cindy Hyde-Smith and her Democratic challenger Mike Espy are both vying for the seat in a deep-red state where President Donald Trump took nearly 58% of the vote in 2016.

The stakes are high. If Espy, a former congressman and Clinton administration alum, comes out ahead, he would become Mississippi's first elected Democratic senator since 1972.

Hyde-Smith, the state's former agriculture and commerce commissioner who was appointed to the Senate seat in March after Sen. Thad Cochran resigned, is favored to win, despite recent criticism she received after telling a supporter she would attend a "public hanging," if invited.

That remark conjured Mississippi's history of racism, lynchings, and Jim Crow laws - andcaused a handful of companies to withdraw their support of Hyde-Smith's campaign. She has apologized for the comment.

Espy has sought to capitalize on the fallout from Hyde-Smith's missteps, as well as subsequent revelations that his Republican opponent attended a "segregation academy" and celebrated the Confederacy.

But he, too, faces significant headwinds on the road to Washington.

An assessment from FiveThiryEight indicates that Espy would need an "unprecedented" swing in order to win Tuesday night.

Some Democrats have held out hope for Espy. The runoff in Mississippi loosely resembles the December 2017 special election in neighboring Alabama, where voters chose Democrat Doug Jones over the embattled Republican Roy Moore, whose campaign was crushed under the weight of a sexual misconduct scandal.

That election gave Alabama its first Democratic senator in more than two decades.