A member of the Republican Party, he represented the 37th district in the Nevada Assembly, covering parts of the northwestern Las Vegas Valley, from 2016 to 2018.

He was endorsed by far-right congressmen Paul Gosar and Andy Biggs of neighboring Arizona, as well as former White House Chief of Staff Mark Meadows.

[4] He also tied himself closely to QAnon, a disproven far-right conspiracy theory, attending an October 2021 conference associated with the movement in Las Vegas.

[6][7] Marchant was a candidate for the United States Senate in the 2024 election in Nevada, a seat held by incumbent Democrat Jacky Rosen.

[8] In 2018, Marchant was unopposed in the Republican primary, but narrowly lost his re-election campaign for Assembly District 37 to Shea Backus, a Democrat, by a vote of 14,222 to 14,087.

He won the Republican Primary with 34.8% of the vote,[12] but lost the general election against incumbent Democrat Steven Horsford by a margin of 50.7% to 45.8%.

[20] An investigation by the Associated Press of potential voter fraud in six states disputed by former President Donald Trump and his legal team—Arizona, Georgia, Michigan, Nevada, Pennsylvania, and Wisconsin—found 475 potential voter fraud cases out of President Joe Biden's combined 311,257 vote victory margin in those six states.

[23] Jim Marchant has often been linked to QAnon, a fringe conspiracy theory that began on the far-right of the internet that claims that a cabal of Satanic child sex traffickers are conspiring against former President Donald Trump.

On Gab, one account that Marchant follows is a pro-Nazi QAnon influencer called IPOT1776, who has argued that Jewish people were spreading Communism and "degeneracy" and that the Nazis were a natural reaction to the "Judeo-Bolshevik menace".

[24] On October 25, 2021,[25] Marchant attended and spoke at "For God & Country: Patriot Double Down", a QAnon event in Las Vegas.

[27] Marchant told attendees that on November 4, 2020, the day after he lost his bid for Nevada's 4th congressional district, he was in his hotel room when he heard a knock at his door.

"[28] In May 2021, Marchant and Savin convened a meeting with conservative media figures, activists, and donors to strategize winning Secretary of State elections nationwide.

All the coalition's members believe the baseless conspiracy theory that the 2020 United States presidential election was stolen from former President Donald Trump by voter fraud.

"[32] This is a reference to an unfounded conspiracy theory that before his death in 2013, Venezuelan leader Hugo Chavez manipulated Dominion Voting Systems machines, which were planted by billionaire philanthropist George Soros to switch votes from former President Donald Trump to President Joe Biden.

He also claims the "cabal" purposefully used COVID-19 to destroy the country and that President Joe Biden is a puppet of the World Economic Forum, which Marchant calls "elitist globalists that control everything".

[32] In 2024, Marchant expressed an antisemitic conspiracy theory, claiming that a secret cabal “had a plan for thousands of years, actually… they’re evil people.

Marchant said that this group "started with the Khazarians," referencing a fringe theory that the Khazars were the ancestors of modern Ashkenazi Jews.