The Andrew County Republican said he plans to step away from the race for the 12th District seat. Instead, he will seek reelection to Missouri's 9th District State House seat.
"Though my campaign for State Senate is ending today, I look forward to continuing to fight for Missouri families in the State House by promoting policies that create jobs, cut taxes, and encourage strong agricultural growth," said Johnson in a news release.
Johnson has served in the Missouri House of Representatives since Jan. 2011.
On the heels of his announcement Thursday, St. Joseph Detective Frank Till said he will no longer run for Johnson's 9th District seat. Till said he told Johnson he would never run against him and said he plans to stand by that promise now that Johnson plans to seek reelection.
Till announced plans to run for the seat in early February. He said he has not ruled out a future run for office.