On Friday, Sen. Pat Roberts, R-Kan., announced he will not seek re-election to the United States Senate for a fifth term in 2020.

Roberts, 82, made the announcement in Manhattan, Kansas, speaking at the Kansas Department of Agriculture. Roberts is Kansas' longest-serving member of Congress, first elected in 1981.

"I am announcing I will serve the remainder of this term as your senator, fighting for Kansas in these troubled times. However, I will not be a candidate in 2020 for a fifth Senate term," Roberts said.

"I have had the honor and privilege of representing Kansas for sixteen years in the House, twenty-two years so far in the Senate. Never, never in my wildest dreams did I think I would become the longest-serving member of Congress in our state's history."

Roberts, the chairman of the Senate Agriculture Committee, was the architect and chief force behind the $900 billion farm bill that passed Congress last month. His retirement leaves vacated a Senate seat that Democrats have not held since the 1930s.

A contentious Republican Senate primary is on the horizon. Politico reports names of potential Republican candidates include Rep. Roger Marshall, R-Kan., Secretary of State Mike Pompeo, Rep. Kevin Yoder, R-Kan., unsuccessful gubernatorial candidate Kris Kobach, and others.

Conservatives should begin the hard work of recruiting a candidate now.