President Trump is rallying in Mississippi Tuesday evening in support of Republican Senate candidate Cindy Hyde-Smith. Both Senate seats in Mississippi have elections this year; Republican Sen. Roger Wicker is up for re-election, and Hyde-Smith is seeking victory in a special election, after she was chosen by Gov. Phil Bryant in March to fill Sen. Thad Cochran's seat after he retired.

The special election will be held on Nov. 6, which is also Election Day throughout the country. It is a runoff election, meaning that if none of the four candidates receive over 50 percent of the vote, the top two vote getters will advance to another special election later in the year. Party labels do not appear on the ballot. Whoever wins will then serve through the remainder of Cochran's term, which ends in 2021.

Hyde-Smith's victory is no sure thing, since she is facing a challenge from the right by another Republican candidate, Chris McDaniel, and Democrats have put forward a surprisingly strong candidate in former Rep. Mike Espy, who was the agriculture secretary during the Clinton administration. McDaniel unsuccessfully challenged Cochran in the 2014 Republican primary, and was planning on running against Wicker in the 2018 election. However, when Cochran stepped down, McDaniel switched races.

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McDaniel is a controversial figure nationally, but he has a solid base of support in Mississippi. He gained national attention as a nationally-syndicated conservative talk radio host in the mid-2000s, until he was elected to the state Senate in 2008. In his broadcasts, he accused the Democratic Party of being the "sex on demand, the party that supports the homosexual agenda." He has also said "I'm not even sure Janet Reno was a woman," referring to the Clinton administration's attorney general. McDaniels' archived show website lists the League of the South, a pro-secessionist website, as one of his favorite sites.

While Hyde-Smith is far from moderate -- FiveThirtyEight reports that she votes in line with Mr. Trump 100 percent of the time -- she is not as far to the right as McDaniel. Although he lost to Cochran in 2014, it was by a narrow margin -- Cochran led him with 51 percent to 49 percent. McDaniel's presence in the special election race could divide the Republican vote in the state, even with Mr. Trump endorsing his opponent in August.

.@cindyhydesmith has helped me put America First! She’s strong on the Wall, is helping me create Jobs, loves our Vets and fights for our conservative judges... — Donald J. Trump (@realDonaldTrump) August 23, 2018

The divided Republican electorate could benefit Espy. Espy may have a slight advantage over Southern Democrats who have run in the past few cycles, given that he is running in a year that voter enthusiasm among Democrats has been strong. Democrat Doug Jones also won a Senate special election race in neighboring Alabama in 2017, showing that a Democrat could win statewide in the deep South. Of course, neither Hyde-Smith nor McDaniel has been accused of sexual misconduct, as Jones' opponent Roy Moore was, but the divided Republican race could have the same net effect for Espy.

Mississippi is also more Democratic than Alabama; Mr. Trump won Alabama by 28 points in 2016, and by 18 points in Mississippi.

If elected, Espy would also be the first black senator to represent Mississippi since the Reconstruction era. Nearly 40 percent of the population in Mississippi is African American, a bloc which tends to vote for Democrats. Jones won in 2017 in large part because of high turnout from black voters -- he garnered support from 96 percent of black voters, and 98 percent of black women. African Americans made up 29 percent of voters total in 2017, a slightly higher percentage than voted for Barack Obama in 2012.

Espy could benefit from the enthusiasm of black voters and newly energized Democrats, as well as the divisions within the Republican Party. An NBC News/SurveyMonkey poll published Tuesday found that Espy is leading Hyde-Smith by a narrow margin, with 25 percent support among registered voters, compared to 24 percent support for Hyde-Smith. McDaniel has 19 percent support, while another Democratic candidate, Tobey Bartee, has 4 percent support. Twenty-seven percent of registered voters are undecided, according to the poll.

The CBS News Battleground Tracker rates the race as "likely Republican."