Johnson first ran for state representative in 2000 after incumbent Representative Steve Trimble, also a Democrat, did not seek reelection. He defeated Democrat Aly Xiong in the primary election and Republican Scott Zimmer in the general election.
In 2000, Johnson made his first foray into state politics after the decision by incumbent Representative Steve Trimble, also a Democrat, not to run for re-election. He successfully navigated the primary election against Democrat Aly Xiong and Republican Scott Zimmer in the general election.