[2] Former Oklahoma Governor David Walters said her loss in the Democratic primary to Robert S. Kerr III "precipitated a real turn on her part.

[5] She resigned in January 2021 due to legal concerns about her involvement in the call Trump made to attempt the reversal of the Georgia's certified votes in the 2020 United States presidential election.

[10][11] Mitchell represented Donald Trump in 2011, defending him against accusations that he had violated federal election laws in an exploratory campaign for president.

[14] Mitchell was a staunch opponent of public health measures implemented at the state and local levels to halt the spread of COVID-19.

[4] She has represented Sen. Elizabeth Dole (R-NC), Sen. Jim Inhofe (R-OK), Sen. David Vitter (R-LA), Sen. Gordon Smith (R-OR), Sen. Jim DeMint (R-SC), Sen. Roy Blunt (R-MO), Sen. Marco Rubio (R-FL), Sen. Pat Toomey (R-PA), Sen. Kelly Ayotte (R-NH), and Rep. Tom Cole (R-OK).

[22] As a board member of the American Conservative Union (ACU), Mitchell played a major role in efforts to expel GOProud (a pro-gay rights Republican group) from the Conservative Political Action Conference (CPAC), a major annual right-wing convention organized by the ACU.

[6] Mitchell is chair of the conservative activist group Public Interest Legal Foundation, which is known for making claims of voter fraud.

[24] Mitchell has worked closely with Ginni Thomas, wife of Supreme Court justice Clarence Thomas, in the Council for National Policy to organize efforts to keep Trump in power,[25] and The New York Times reported that it was Mitchell who "enlisted John Eastman, the lawyer who crafted specious legal theories claiming Vice President Mike Pence could keep Mr. Trump in power.

[12] Mitchell blamed her resignation on a purported "massive pressure campaign" allegedly launched by leftist groups on social media.

FreedomWorks put her in charge of a $10 million initiative to push for voting restriction and train conservatives in local elections.

[32][33] Mitchell also set up an escrow fund to funnel money to companies conducting a pro-Trump "audit" into the 2020 presidential election in Maricopa County, Arizona.

[35] The Conservative Partnership Institute, a right-wing think tank formed by Jim DeMint,[36][37] helped to create the Election Integrity Network project, an effort spearheaded by Cleta Mitchell beginning in 2021.

[38] Both Mitchell and former White House chief of staff Mark Meadows are senior members of the Conservative Partnership Institute, which received funding from Trump's Save America PAC.

[26][39] According to The New York Times, Mitchell is preparing for future elections, and has support from other well-funded right-wing organizations as well, including the Republican National Committee.

[26] Speaking about these organizing efforts, during a June 2022 episode of Stephen Bannon's War Room podcast, Mitchell stated: "2020 — never again.

"[41] Some of the ambitions of this newly formed Election Integrity Network may be achieved based on tactics such as poll-monitoring, and filing public records requests, but there are concerns that the group will also focus on researching "local and state officials to determine whether each is a 'friend or foe' of the movement."

Mitchell's Election Integrity Network trainings have included "aggressive methods" such as surveillance, and encouraging participants to verify voter rolls themselves.

This may put extra pressure on local officials and be disruptive to the voting process, especially "when conducted by people convinced of falsehoods about fraud.