Sen. Pat Roberts, the blunt-speaking Kansas Republican who has served in Congress for nearly four decades and recently shepherded a sweeping farm bill to passage, announced Friday that he will not seek reelection in 2020, opening a seat the GOP has held for nearly a century.

Appearing alongside his wife, Franki, an emotional Roberts announced that he would retire at the end of his term — his fourth in the Senate, after serving 16 years in the House.

“I am announcing I will serve the remainder of this term as your senator, fighting for Kansas in these troubled times,” Roberts said at a news conference in Manhattan, Kan., before explaining that he would not seek to extend his tenure.

Top Republicans were not surprised by his decision. Many had already started considering who would run in his place and expressed confidence the seat would remain in GOP hands.

Republicans close to Senate GOP leaders expressed strong interest Friday in the prospect of trying to persuade Secretary of State Mike Pompeo to run for the seat. Representatives for Pompeo did not immediately respond to an inquiry seeking to gauge his interest.

Democrats have not won a Senate seat in Kansas since 1932, but the state has undergone a political change in recent months, electing Democrat Laura Kelly governor in 2018. Since then, several female Republican state lawmakers have switched parties in frustration with President Trump and the GOP.

Senate Republicans were interested in Pompeo, they said, because they believe he could clear the primary field and spare the party an ideologically divisive and bruising battle. They reasoned that few would want to take on Pompeo, a former congressman from Kansas and a close ally of Trump.

The Republicans who mentioned Pompeo spoke on the condition of anonymity to candidly discuss their perspectives on the race.

It was unclear whether Pompeo would be interested. He has shown no public signs of wanting to leave his post.

Other names that surfaced as GOP possibilities included Kansas Secretary of State Kris Kobach, a Trump ally who lost the race for governor last year; Rep. Roger Marshall; and Gov. Jeff Colyer, whom Kobach defeated in the gubernatorial primary.

Throughout his Senate career, Roberts has kept a lower national profile than many of his colleagues. But he has left a clear mark on the chamber’s legislative decisions.

As the chairman of the Senate Agriculture Committee, Roberts recently helped spearhead an $867 billion farm bill into law, with the measure securing the backing of all Senate Democrats, a remarkable feat in a sharply divided Congress. The legislation allocates billions of dollars in subsidies to American farmers, legalizes hemp, bolsters farmers markets and rejects stricter limits on food stamps pushed by House Republicans.

Conservatives were unhappy with the bill’s provisions on food stamps, and the Trump administration had signaled its intention to cut them without approval from Congress.

Roberts alluded to his bipartisan work at the news conference where he announced his decision.

“I have a lot of trust and faith in Senator [Debbie] Stabenow,” Roberts said of the Agriculture Committee’s ranking Democrat as he boasted about passing his eighth farm bill. He also called the panel “the least partisan committee in Washington.”

Roberts said he spoke to former senator Bob Dole before making his announcement and the 95-year-old Dole joked about seeking the open Senate seat.

In 2014, Roberts faced his first serious electoral test since arriving in the Senate. Milton Wolf, a doctor and distant relative of Barack Obama who was active in the tea party movement, mounted a Republican primary challenge against Roberts. He criticized Roberts for voting to increase the debt limit while failing to repeal the Affordable Care Act and for seeking a fourth term when he had pledged to serve just two.

“Our party was supposed to stand up for limited government and lower taxes,” Wolf said when announcing his long-shot campaign. “Our party failed.”

Roberts was slow to build his 2014 campaign and defeated Wolf by only seven percentage points — a smaller margin than polls or party strategists expected, after a campaign that revealed that the senator no longer owned a home in Kansas.

That emboldened Democrats, whose candidate for Senate quit the race and endorsed Greg Orman, a businessman running as an independent. National Republicans swooped in to help Roberts, pushing him to a 10-point victory — the smallest winning margin for any senator in Kansas in 40 years but enough to put him back in the Senate.

Republicans hold a 53-to-47 advantage over the Democratic caucus in the Senate. They are defending 22 seats in 2020, compared with 12 for Democrats.

Roberts’s decision comes just a few weeks after Lamar Alexander of Tennessee, another longtime GOP senator known for bipartisanship, said he would not seek reelection in 2020.