Hyde-Smith will beat his Democratic opponent Mike Espy, a former Congressman and Secretary of Agriculture, in the last Senate race to be decided in 2018. This victory will make her the first woman to be elected to the Mississippi Congress.
His victory on Tuesday means Republicans will hold 53 seats on the Senate's 47-seat Senate Democrats in January. The GOP has increased its Senate majority by two seats in this year's mid-term elections, even as Democrats take control of the House.
The victory of Hyde-Smith also means that there will be 24 women in the Senate next year. This will set a new record for women serving in the Senate, a record higher than the current record set during this Congress.
Hyde-Smith will complete the last two years of the term of former Senator Thad Cochran, who retired earlier this year for health reasons. Hyde-Smith will have to run again in 2020 for a six-year term.
President Donald Trump traveled to Mississippi on Monday to gather Republican voters behind Hyde-Smith after his comments on a "public hanging" sparked weeks of controversy.
It all started when a video was aired online about her supporters, saying early this month that she would be "in the forefront" if any of her supporters "invited me" to a public hanging ". She later described these comments as an "exaggerated expression of respect," but her use of this phrase served to recall the lynching history in Mississippi and to place the contest under the national microscope.
Asked about her remark during a debate, Ms. Hyde-Smith said that she would "apologize" to anyone who was offended, but then turn to attack her opponent.
"This comment was twisted and turned into a weapon to use against me," said Hyde-Smith.
Hyde-Smith's comments prompted him to deepen his story.
The same progressive blogger who published his video using the phrase "public hanging" subsequently published a sentence in which Hyde-Smith told a small group of the State University of Mississippi that suppressing the votes of students from other colleges was "a great thing". His campaign said it was a joke, but that explanation turned against the spirit of a black student who saw laughter. Image of the event that his campaign posted on Twitter responded that the Hyde-Smith campaign was using it as an accessory.
On Friday, the Jackson Free Press reported that Hyde-Smith had attended a private high school founded in 1970 so white parents avoided attempts to integrate public schools. Hyde-Smith's daughter then attended a similar private school established around the same time, according to the Free Press. The senator's campaign reacted to the report by attacking the "liberal media".
Over the weekend, CNN reported that Hyde-Smith had once promoted a measure hailing the efforts of a Confederate soldier to "defend his homeland" and pushed for a revisionist view of the Civil War.
In photos posted on his Facebook account in 2014, Hyde-Smith was photographed posing with Confederate artifacts during a visit to Beauvoir, the home and library of Confederate President Jefferson Davis. The article's caption read: "The Mississippi Story at Its Best!"
Democrats had hoped for an increase in the turnout of black voters – who account for nearly 40 percent of Mississippi's population, the largest part of the country – could lead Espy to victory in a highly polarized state on racial grounds, with most white voters supporting GOP candidates and black voters supporting Democrats.
Espy's campaign hammered Hyde-Smith with TV commercials putting her in an embarrassment for a state that attempted to surpass its history of slavery and racism.
"We have worked hard to overcome the stereotypes that are hurting our economy and costing us jobs, nor should our words reflect the values of Mississippi," said one narrator in an advertisement. The advertisement also called Hyde-Smith "so embarrassing, it would be a disaster for Mississippi."
Several companies that donated to the Hyde-Smith campaign, including Walmart, publicly withdrew their support for the senator's comment on the "public hanging."
The controversy surrounding it has prompted Republicans to pressure them to avoid the same embarrassment they suffered last year in Alabama because of Roy Moore's campaign in the Senate and the Hyde-Smith rescue.
Although Hyde-Smith remained largely outside the election campaign, the party's infrastructure rallied to his defense. GOP groups spent $ 4 million on Mississippi runoff – far more than the $ 1.2 million of Democrats, according to documents filed by the Federal Election Commission. Republican groups have spent more than twice as much as Democrats on television ads, according to the Kantar / CMAG advertising tracking firm.
Trump's visits to Mississippi on Monday night were also seen as an attempt to rally the Republican base to vote during an election that will take place two days after Thanksgiving weekend.
Adam Levy from CNN contributed to this report.