Fitton is a long-term senior member of the Council for National Policy, a conservative umbrella organization for groups such as Judicial Watch.

[4][5] In 2022, researchers found that Fitton was the third-most prolific purveyor of election misinformation on Twitter during the late months of 2020.

In a November 1998 appearance on Politically Incorrect with Bill Maher in which he was accusing President Clinton of sexual improprieties, Fitton was asked when the last time he had sex was, and refused to answer.

[17] In July 2013, Fitton falsely claimed that the Obama administration's Department of Justice had sent representatives to Sanford, Florida, following Trayvon Martin's death "to help organize and manage rallies and protests against George Zimmerman.

[8][18] The study had debunked one of the common claims made by climate change deniers: that there had been global warming "hiatus" from 1998 to 2012.

"[8] The Judicial Watch lawsuit was inspired by US Representative Lamar Smith, who accused the authors of the study of "alter[ing] data" to "get the politically correct results they want.

Iowa's secretary of state, Paul Pate, a member of the Republican Party, debunked Fitton's claim by linking to official voter registration data.

[24][25] In a video recording released in October 2020, in the lead-up to the 2020 election, Fitton called on fellow conservative activists at a conference to come up with ways to prevent mail-in-ballots from being distributed to voters.

[27] Fitton has been identified as unindicted co-conspirator #1 in the Georgia state indictment of Donald Trump and 18 other defendants for their attempts to overturn the 2020 presidential election.

[30] In 2017, Judicial Watch helped to stoke Republican attacks against Special Counsel Robert Mueller's investigation into Russian interference in the 2016 election.

"[38] During the COVID-19 pandemic, Fitton called on Trump to "reopen" the United States amid social distancing and lockdowns to prevent spread of the virus.

[40][41][42] At an August 2020 meeting of the Council for National Policy, Fitton claimed that people on the American left are planning to delay the 2020 election tally until January 20, 2021, to allow House Speaker Nancy Pelosi to become acting president.

[43] Upon leaving office in January 2021, Trump took numerous boxes of government documents to his Mar-a-Lago home in Florida.