[3] Nelson became the representative for the 57th House District of Pennsylvania during a special election in March 2016, taking over the seat after Rep. Tim Krieger resigned to serve as a common pleas court judge.
[4] He won a full term in November 2016 with sixty-five percent of the vote over opponent Linda Iezzi.
[4][5] In November 2018, Nelson was elected to a second term, receiving sixty-two percent of the vote over his opponent Collin Warren.
[4] In April 2020, Nelson introduced an amendment to the Heart and Lung Act that would ensure police and firefighters would continue to be paid if they had to miss work because of the COVID-19 pandemic.
This also occurred after federal appeals brought by the Trump campaign were dismissed due to lack of evidence.