McCalmon attended Brandman University where he earned a Bachelor of Science in Business Administration. His first campaign for the State House was in 2022, when he ran to succeed Glen Casada as the representative for the 63rd district.[2] McCalmon won the Republican primary and went on to defeat Democrat Kisha Davis in the general election.[3]
McCalmon lives in Williamson County with his wife, Rachelle, and their three daughters.[4]
In 2023, McCalmon supported a resolution to expel three Democratic lawmakers from the legislature for violating decorum rules. The expulsion was widely characterized as unprecedented.[5]