When incumbent State Representative Fred Brummer was unable to seek another term in the legislature and instead opted to run for the Orange County Commission, Nelson ran to succeed him in the 38th District, which was based in northern Orange County, stretching from Apopka to Ocoee, Orlando, and Maitland.

When Nelson ran for a third term in 2010, he did not face a Democratic opponent, but instead a member of the Florida Tea Party, James Heinzelman.

Nelson ran on a platform of "repealing parts of SB 550, which would impose a five-year inspection schedule on septic tanks," which he said would lead to a "bureaucratic and costly nightmare" and on supporting SunRail, which Heinzeilman vocally opposed.

He was able to defeat his Democratic opponent, Vice Mayor Alvin Moore, Sr. of Eatonville, Florida in the general election process in 2014.

[6] During his second term beginning in 2022, Nelson generated large amounts of controversy regarding the death of Austin Duran [1], a member of the Apopka Fire Department who died after a work related accident.