MANHATTAN, Kan. (AP) — Longtime Republican Sen. Pat Roberts of Kansas said Friday that he will not seek re-election in 2020, ending a decades-long career in Congress and setting up an intense political scramble to replace him.

The 82-year-old senator has spent decades in Congress but faced pressure to step aside in part because he would have been 84 when facing voters in 2020. He also faced grueling primary and general election contests in 2014, when his congressional longevity became a liability.

Roberts is the second veteran Republican senator in less than a month to announce plans not to run again in 2020, following Tennessee’s Lamar Alexander.

Republicans have won every U.S. Senate race in Kansas since 1932, often by comfortable margins. Roberts won a U.S. House seat representing western Kansas in 1980 and was elected to the Senate in 1996. But his seat was in play in 2014 as Republicans sought to reclaim a Senate majority, after opponents on both the right and left painted him as an out-of-touch Washington insider.

Critics mocked him for claiming his home was in Dodge City, the iconic former Wild West town, even though he maintained a residence in the Washington area. Roberts hurt his re-election bid by joking that renting space in the home of two Dodge City supporters gave him full access to a recliner. He bought a home in Topeka in 2016.

In 2014, Roberts captured less than 50 percent of the vote in a four-person primary after a spirited challenge from tea party candidate Milton Wolf, a Kansas City-area radiologist. The Democratic nominee dropped out, giving stronger independent candidate Greg Orman, a Kansas City-area businessman, a cleaner shot at Roberts. The national GOP quickly retooled Roberts’ campaign.

The resulting national spotlight was unlike anything Roberts had seen during his previous campaigns.

Potential Republicans that could replace Roberts include departing Gov. Jeff Colyer, outgoing Kansas Secretary of State Kris Kobach and Rep. Roger Marshall, who holds the same western Kansas seat Roberts once did. Among Democrats, Barry Grissom, a former U.S. attorney for Kansas, was considering the race before Roberts’ announcement.

After working 13 years as a congressional staffer, Roberts in 1980 won the safe GOP seat for western Kansas in the House held by his retiring boss. He kept the seat for 16 years and made his mark on farm policy, eventually rising to House Agriculture Committee chairman.

He won his Senate seat in 1996 when popular moderate Republican Sen. Nancy Kassebaum Baker decided not to seek re-election. Democrats did not field a candidate against him in 2002, and he handily won re-election in 2008.

He continued to focus on agriculture as a senator and just weeks ago helped negotiate the final terms of a massive farm bill as Senate Agriculture Committee chairman. The legislation reauthorized agriculture and conservation programs worth $400 billion over five years but failed to tighten work requirements for recipients of food stamps, a goal of some Republicans.

He also served four years as the Senate Intelligence Committee chairman, presiding over intensely partisan hearings over the intelligence before the 2003 invasion of Iraq. He left the chairmanship in 2006, after anger over the war cost Republicans their Senate majority.

But his 2014 gaffe about the recliner showed how his sharp tongue could sometimes get him into trouble. After then-President Barack Obama had a contentious lunch in 2010 with GOP senators, Roberts called the Democrat “pretty thin-skinned” and told reporters, “He needs to take a Valium before he comes in and talks to Republicans.”