TOPEKA, Kan. — Competitive races for two of Kansas' four U.S. House seats are making Republicans sweat to keep their all-GOP state delegation, a twist in a state where President Donald Trump won by nearly 21 points and a leading candidate for governor is gun-rights and immigration hardliner Kris Kobach.

In one case, the Republican incumbent who faced a tighter-than-expected race two years ago faces a field of Democrats energized by dislike of Trump on issues including immigration, health care and the environment. In the other, potential big-name candidates opted not to run for the open seat, leaving a Democrat with the best name recognition.

Republicans say they can feel their opponents' energy and have been issuing warnings to their conservative base for months.

"Both of those races are ones that we have known we have to be diligent in and work hard," state GOP Chairman Kelly Arnold said. "Who has the motivation to come out? The party that's not in power usually picks up seats and some wins. That's what we're fighting against."

To boost Democrats' chances in both districts, the House Majority super PAC announced plans to reserve $900,000 in television ad time in the Topeka and Kansas City markets in the weeks before the election, far more attention than Kansas Democrats running for Congress have received in recent elections. The conservative Congressional Leadership Fund then promised nearly $3 million worth of ad time.

Democrats need to pick up 23 seats nationally to flip the majority in the House.

Incumbent Republican Kevin Yoder was destined to be a midterm target after Trump narrowly lost his Kansas City-area 3rd District and its urban neighborhoods and comfortable-to-posh suburbs. Yoder himself fared worse than expected. Democrats sensed Trump might be a liability and both sides poured money into the race at the last minute in 2016, giving Yoder an 11-point margin against an unknown Democrat — less than half his previous average.

But Democrats' chances could be better in the neighboring 2nd District, which covers most of eastern Kansas from the Nebraska border in the north to Oklahoma in the south. Incumbent Republican Lynn Jenkins opted not to seek re-election. Democrats have their ideal candidate in former state legislative leader and governor candidate Paul Davis . The Democratic Congressional Campaign Committee included Davis on its first list of 11 candidates in promising races for its "Red to Blue" program. Seven lesser-known Republicans are vying for their party's nomination.

"Republicans, generically, have the wind in their face," said Patrick Miller, a political scientist at the University of Kansas. "If this were 2010 or 2014, we wouldn't even be talking about the 2nd District."

Davis carried Jenkins' district during his narrow statewide loss to Sam Brownback in the 2014 race for governor. Republicans who might have had equally strong support — Attorney General Derek Schmidt and State Treasurer Jake LaTurner, for example — opted out, citing family or professional reasons. The GOP field has four state lawmakers, an ex-Kansas House speaker, a new-to-politics military veteran and a small-town city councilman-nurse-criminologist.

The GOP candidates have scrapped for attention and more than half of their dollars through March came from their own pockets. Davis has raised more than $1 million.

"He has name ID," Arnold said. "We don't know where we're at with our candidate because we don't know who it is yet."

Yoder's aides and supporters say he's working hard to sidestep any potential Democratic wave. He began April with nearly $2 million in campaign cash.

Nevertheless, six Democrats want a crack at Yoder, including labor lawyer Brent Welder, who drew the endorsement of U.S. Sen. Bernie Sanders and is listed among the group of "Justice Democrats" in the mold of 28-year-old Alexandria Ocasio-Cortez, who defeated incumbent Rep. Joseph Crowley in the Democratic congressional primary in New York.

Yoder also picked up two opponents for the Aug. 7 GOP primary. One, Trevor Keegan, an information technology consultant, describing himself as a moderate alternative.

The heavy lift for the GOP in the congressional races comes even as the most talked-about candidate for governor is conservative Kobach, and state lawmakers have shown no sign of softening on issues that animate the base like immigration and guns. Wednesday's announcement that Supreme Court Justice Anthony Kennedy is retiring is expected to energize GOP voters across the country, which could ease the Republicans' path in Kansas.

And Republican congressional candidates are not breaking with the president, arguing that voters like his handling of North Korea and Iran and the income tax cuts he pushed. Trump carried Jenkins' district by nearly 17 points two years ago, and Republicans expect a revived national economy to help.

Davis avoided bashing Trump in a recent interview, saying that Washington is dysfunctional and both parties share the blame.

"Donald Trump is president, and if I'm elected, I'm going to do my best to work with him when he's doing good things," Davis said. "I'm going to call him out when he's doing harmful things."