Democrats hoping to seize the U.S. House majority this fall need Donald Trump’s help. More precisely, they need a historic anti-Trump landslide.

That’s because to have any chance of winning the 218 seats needed for a majority, Democrats would have to defeat supposedly “safe” Republicans like Rep. Kevin Yoder in Kansas. That’s no easy task, since Yoder won re-election by 20 percentage points in 2014.

“Republicans will lose the House if Yoder loses,” Patrick Miller, a University of Kansas political scientist, said of the three-term conservative congressman who represents the Kansas City suburbs.

Yoder’s district is exactly the kind that makes the prospect of dislodging the Republican majority so daunting. It was redrawn in 2012, stripping out liberal voters from the county that includes the town of Lawrence and the University of Kansas and leaving it firmly conservative. The House is full of such seats engineered to stay in Republican or Democratic hands, which helps explain why at least 90 percent of House incumbents won re-election in 2012 and 2014.

Democratic and Republican campaign strategists, academics and other independent political scientists identified Yoder’s race as an example of the kind of long-shot contests that Democrats must win to recapture the House majority they lost in 2010. Others include seats held by Darrell Issa of California and an open seat in a conservative Indiana district.

At this point, Republicans seem likely to hold onto all three of those seats.

Congressional Democrats are doing their best to aggressively tie Republican congressional candidates closely to their party’s controversial presidential candidate. Still, they would need a net gain of 30 seats to reverse what is currently the largest Republican majority since 1928 — 247 seats to 186. Two seats, formerly held by Democrats, are vacant.

More realistically, party strategists and independent experts are predicting a net pickup of about 12 to 16 seats — even if Hillary Clinton soundly defeats Trump. Democrats could oust Republicans in upstate New York, Illinois, Nevada, Florida, Colorado, Pennsylvania, Virginia, Iowa, Minnesota and Texas.

Even Democratic vice presidential nominee Tim Kaine has said he expects the House to remain in Republican hands, though the margin will be narrowed.

Back in Kansas, Yoder is running against a local businessman and political newcomer, Jay Sidie. Still, the incumbent has been exhibiting some public concern over Trump’s standing in his district, as well as jitters over the plummeting popularity of his state’s Republican governor, Sam Brownback.

In fact, Yoder’s campaign manager, Cate Duerst, points out the congressman has taken the unusual step of publicly releasing an internal poll showing him with a 53-36 percentage point lead on Sidie.

Trump currently trails Clinton in the district, 44-38.

Duerst insists that any path to a new majority in the House led by Democrat Nancy Pelosi will not be paved through his district.

“If Washington Democrats want to waste their money pushing a Clinton-Pelosi agenda in Kansas, they are welcome to,” she said. “All that means is the Republican Party will surely keep control of the U.S. House of Representatives in November.”