Merrill interned for the United States Congress from May to July 1983, where he met representative William Flynt Nichols, who became his mentor.

[6] He succeeded James R. Bennett, who had been appointed to the office to fill out the remainder of the term of the Republican incumbent representative Beth Chapman.

King and Norman E. Youngblood at Auburn University, found the content and quality of Alabama's county election and voting websites were lacking with relevant information regarding deadlines, polling stations, and voter requirements.

The election was widely considered to not be free and fair, and the OSCE report found systemic problems with "serious irregularities during voting" and even worse practices during ballot counting.

He was one of several candidates for the Republican nomination; others included Roy Moore, Bradley Byrne, Tommy Tuberville, and Arnold Mooney.

[17][18] In July 2019, at a campaign event in Fort Payne, Merrill said that "homosexual activities" pervasive in mainstream media had partly lead to the nation's moral decline.

When asked in a follow-up interview, Merrill pointed to the media coverage of the U.S. women's national soccer team win in the World Cup as an instance.

[19] Merrill contended that were no longer any television shows "that are based on biblical foundations" which "promote family and culture with a father, a mother, and children" present.

[18] In 2021, Merrill announced that he was canceling his planned 2022 Senate campaign, after being publicly exposed as having had an extramarital affair over a four-year period.

[20] During the COVID-19 pandemic, Merrill sought to block local jurisdiction in Alabama from allowing curbside voting for immunocompromised voters.

[21] In 2021, Merrill met with Mike Lindell, founder of MyPillow and a Donald Trump adviser, who was known for making outlandish conspiracy theories and false claims about fraud in the 2020 election.