He attended Davidson College, where he graduated with his bachelor"s degree in history in 1989. Following his active duty military service, he attended the Fredric G. Levin College of Law at the University of Florida, receiving his Juris Doctor in 1994.
After graduation, he joined the United States Navy, serving as a Surface Warfare Officer, and provided combat operations support in the Gulf War. Renner then served as an assistant state attorney, where he supervised misdemeanor attorneys and prosecuted felony offenses in the Felony Trial Unit. As a reservist, Renner was mobilized to active duty and served in support of combat operations in Afghanistan in 2011.
In 2014, when incumbent State Representative Daniel Davis declined to seek a third term in the legislature, Renner ran to succeed him in the 15th District, which included parts of downtown Jacksonville in western Duval County.
He faced banker Jay Fant in the Republican primary, and a brutal election soon began. Though the two candidates aligned closely on ideological issues, Renner emphasized his leadership credentials through his military service and his career as a prosecutor.
Renner was endorsed by Davis, whom he aimed to replace. State Senator John East. Thrasher, Duval County Sheriff John Rutherford, and United States Congressman Ron DeSantis, as well as local business organizations.
During the campaign, Renner was attacked by third-party groups over his alleged support for gambling, which he objected to, noting that he had expressed his opposition to the expansion of gambling and had signed a pledge with Number Casinos to indicate his opposition.
He emphasized his support for reducing crime, declaring, "I think the first priority of government has got to be public safety. We"ve got to fight crime in our community, and I"m committed to doing that as well." Ultimately, the election proved to be close, as Fant finished just three votes ahead of Renner. Following a manual recount, Fant"s margin of victory was reduced to two votes, and Renner conceded to him.
When State Representative Travis Hutson resigned his seat to run in a State Senate special election, Renner moved into the 24th District, which was 4 districts to the south of the 15th District, so that he could run to succeed Hutson.
He was opposed by former Saint Johns County Commissioner Ron Sanchez and Danielle Anderson in the Republican primary, and emphasized his support for economic development, education, veterans issues, and tourism, noting that the district needs to get its "fair share" of state appropriations. In contrast to the close election less than a year earlier, Renner cruised to victory in a landslide, receiving 70% of the vote to Sanchez"s 18% and Anderson"s 12%.
He advanced to the general election, where he faced Adam Morley, the Democratic nominee and small business owner. Renner was endorsed by the Florida Times-Union, which praised his "detailed, diverse resume that makes jaws drop" and suggested that he would be a "sensible and pragmatic legislator," and by The Saint Augustine Record, which noted that he "has proven commitment and leadership in his military career." Renner ended up defeating Morley by a comfortable margin, receiving 67% of the vote to Morley"s 33%.