Rep. Steve King is no stranger to controversy. The Republican congressman’s recent comments about rape and incest have Republican leaders calling for his ouster, and this is just the latest entry on King’s laundry list of insensitive and racist statements. Nevertheless, King says he’s running for reelection in 2020.

But this could be the end of the line for King. He faces a serious challenge in the Republican primary and, if he overcomes that, a potential general election rematch with J.D. Scholten, the Democrat who gave King a close race in 2018.

Indeed, King’s problems predate 2019. In the final stretch of the 2018 campaign, he came under fire for comments saying diversity is not a strength and for his ties to far-right political figures in the wake of a shooting at a synagogue in Pittsburgh. National Republicans disavowed him, and King only narrowly defeated Scholten by 3 percentage points — a far cry from King’s typical 20-plus-point margins of victory in Iowa’s 4th District, which was about 22 points more Republican than the country as a whole in 2018. As the table below shows, King’s performance was the third-worst of any Republican incumbent seeking reelection in 2018 relative to the partisan lean of the incumbent’s district.

King had one of the worst performances in 2018 Top 10 underperforming Republican House incumbents in 2018 elections measured by the difference between their vote share margin and partisan lean of their districts District Republican Margin Partisan Lean Performance NY-27 Chris Collins +0.4 R+22.9 -22.5 UT-04 Mia Love -0.3 R+20.1 -20.4 IA-04 Steve King +3.3 R+22.5 -19.1 TX-31 John Carter +2.9 R+21.3 -18.4 PA-17 Keith Rothfus -12.5 R+5.8 -18.3 CA-50 Duncan Hunter +3.4 R+21.6 -18.1 GA-07 Rob Woodall +0.2 R+17.2 -17.1 TX-07 John Culberson -5.1 R+11.9 -16.9 TX-32 Pete Sessions -6.5 R+9.6 -16.1 GA-06 Karen Handel -1.0 R+14.5 -15.5 FiveThirtyEight’s partisan lean metric is the average difference between how a state votes and how the country votes overall, with 2016 presidential election results weighted at 50 percent, 2012 presidential election results weighted at 25 percent and results from elections for the state legislature weighted at 25 percent. Source: ABC News

Despite his controversial statements and calls by some Republicans for King to resign, King seems intent on sticking around. But that will be easier said than done. Just prior to the controversial New York Times interview, Republican state Sen. Randy Feenstra decided to seek King’s seat, setting up a primary clash. And the incumbent may struggle to amass the resources to fend off such a serious primary challenge: At the end of June, King had less than $20,000 in his campaign account, far behind Feenstra’s nearly $340,000.

Of course, King could still win his primary. He has long-standing ties to Republican activists, and his conservative bona fides might be enough to overcome his many controversial statements.

Additionally, Iowa election rules could give King a chance even if he fails to win the most primary votes. According to state law, if no candidate wins at least 35 percent of the primary vote, a district party convention decides the nomination. The primary vote would have to be split many ways for that to happen, but it’s a real possibility because two other Republicans are also running — Army veteran Bret Richards and Woodbury County Supervisor Jeremy Taylor. With four Republican candidates in the race, it’s conceivable that no one will surpass 35 percent.

While unusual, such nominating conventions in U.S. House races are not unheard of. In fact, King got his start with one: When King first ran for Congress in 2002, no Republican won more than 35 percent in a four-way primary, and King won the GOP nomination at the ensuing convention. Most recently, a convention was used in 2014 when Republicans in Iowa’s 3rd District picked David Young from a six-candidate field to be the party’s nominee. Conventions can be unpredictable, but activists who participate in those kind of party events tend to be more ideologically extreme than rank-and-file voters, so King might be favored at one.

Should King make it to the general election, he probably would be favored to win as the Republican nominee in a district where President Trump won 61 percent of the vote in 2016. But Scholten’s candidacy on the Democratic side could make for a close contest. In their 2018 race, Scholten raised nearly four times as much money as King, and the former minor league baseball player made headlines when he announced his 2020 bid in a video narrated by Kevin Costner, the star of the film Field of Dreams, which takes place in Iowa. In 2018, Scholten benefited from a heavily Democratic-leaning national environment, and once again he will probably need friendly conditions to have a chance in the strongly Republican district. Still, Scholten’s 2018 performance suggests that he might be the only Democrat who could win the seat.

No matter how 2020 pans out for King, his standing in Republican circles has fallen spectacularly. Despite his history of controversial comments, King was once — excuse the obvious pun — a kingmaker in conservative political circles. This was particularly obvious in previous presidential cycles, when Republicans looking to win Iowa’s caucuses would cozy up to King in the hopes of getting his support. Even if he survives to win another term in Congress, it’s difficult to see King getting that kind of royal treatment again. And he’s looking more vulnerable in 2020 than he ever has before.