[2][3] Lee ran for a seat in the Colorado House of Representatives from the 18th district and defeated Republican nominee Karen Cullen in the 2010 election.

[11] Lee announced his campaign on September 2, 2017, and defeated Republican nominee Pat McIntire.

[21] In 2022, Lee was indicted by a grand jury for registering to vote at an address where he did not live, but Judge Eric Bentley dismissed the case due to incorrect residency information being provided to the prosecution.

[22][17] Lee voted against legislation that required Colorado's public employee pension fund to oppose Boycott, Divestment and Sanctions.

[23] Lee was among thirty-seven legislators who endorsed a letter in 2018, calling for Planned Parenthood to allow for their workers to form a union.