Like some Republicans, J.D. Vance, a candidate for US Senate, was originally opposed to Donald Trump throughout his political ascension, even labeling him "America's Hitler" at one point.

Now, the candidate has Trump's support and mimics his populist style.

Vance, a former Marine and Yale Law School graduate, rose to prominence in 2016 with the release of his memoir "Hillbilly Elegy", which aimed to explain why working-class white people might be drawn to the campaign of a New York real estate magnate like Trump.

Several contenders were seeking the Republican nomination in Ohio, with the battle mostly centered on how close the party should remain to Trump, who continues to claim victory in the 2020 presidential election.

Moderate Republicans, like departing Senator Rob Portman, are concerned that Democrats will be able to win the general election in November if the Republican nominees accept such false assertions.

Read more: Cash pouring into Ohio, Pa. Senate races

During his victory speech, Vance told his supporters that he thanked Donald Trump, saying, "A lot of the fake news media out there ... wanted to write a story that this campaign would be the death of Donald Trump's America First Agenda. Ladies and gentlemen, it ain't the death of the America First Agenda!" 

Vance is up against moderate Democrat Tim Ryan, an incumbent US representative from a blue-collar district, in the November election.

Ohio's second current senator is Democrat Sherrod Brown, who has a similar political style to Ryan, giving Democrats optimism that they might pick up a vital Senate seat from the red-leaning state.

Because the US Senate is now split 50-50 between Republicans and Democrats, each election this November has the potential to shift control of the chamber.