WASHINGTON — After House Speaker Paul Ryan announced Wednesday that he would not seek reelection, he'll follow up with a very different task Thursday: swearing in the newest Democratic representative, Southwestern Pennsylvania's Conor Lamb.

The juxtaposition of the departing GOP leader welcoming a Democrat who won a stunning special election upset last month will briefly encapsulate Republicans' growing fear of a coming political wipeout this fall.

To some, Ryan's decision to step down — even as he chalked up the decision to family factors and not politics — was the strongest signal yet that the GOP is in serious trouble heading into November's midterm races, and struggling in the choppy waters.

"Donald Trump is the muscle of the GOP. Paul Ryan has been its heart and soul. You need all three if you want to be the majority party in America," emailed Republican pollster Frank Luntz.

He argued that Ryan "talked about what he was for, while the party increasingly focuses on what they are against."

Former New Jersey Gov. Chris Christie saw Ryan's departure as a sign that the speaker fears his party will lose the House, plunging the GOP into virtually powerless minority status in the chamber.

"It is a big indicator that the speaker doesn't think he'd be speaker anymore," Christie told ABC News. "If you're a betting person, you're betting on the Democrats for the House in the fall."

If campaign donors take that indicator to heart and see the House as a lost cause, it could move them to steer money to Senate races instead, leading to even more challenges for House Republicans.

"Is this a politically toxic environment for Republicans? Hell yes," said Rep. Charlie Dent, an Allentown Republican who is also not seeking reelection.

Ryan said politics played no role in his decision, and argued that his departure won't affect the outcomes in congressional races this fall.

"This really was two things. I have accomplished much of what I came here to do, and my kids aren't getting any younger," he told reporters. "And if I stay, they're only going to know me as a weekend dad, and that's just something I consciously can't do. And that's really it right there."

The shift in Ryan's status, however, also highlights the striking changes Trump has brought to the political landscape. Six years ago, at 42, Ryan was his party's nominee for vice president and potential face of the future.

Now he is leaving public office amid an uneasy relationship with a president of his own party.

At times Ryan criticized Trump's most acidic statements. At others he conspicuously looked the other way. Mostly he seemed to keep his head down and hope Trump would sign onto the conservative agenda he had so long championed.

Ryan got the major tax cuts he wanted, but many of his other big plans remain unfinished, and his approach seemed to satisfy neither Trump supporters nor critics.

"The challenge for Republicans right now, particularly in swing or marginal districts, is this," Dent said, "They need to put some distance between themselves and the president. They do that, and elements of the base will say, 'You're a traitor,' and the Resistance movement will say, 'You're still a sycophant.'"

Ryan's decision not to run in midterm elections echoes a trend that has already swept the Philadelphia region.

Along with Dent, incumbent Republican Reps. Ryan Costello, Pat Meehan, and Frank LoBiondo have all chosen not to run again. All represent the kind of suburbs where Trump has generally polled poorly and where Democratic voters have turned out in force. Lamb thrived in those kind of areas outside Pittsburgh when he won a seat in a strongly pro-Trump district in March.

"I think that Paul Ryan sees the same data that we're seeing, that it's going to be difficult for Republicans to keep the House this November," said Rep. Brendan Boyle (D., Pa.). "It's one of the main reasons you're seeing so many Republicans in tough seats retire."

In all, more than 40 House Republicans have resigned, announced their retirements or are seeking another office. One, Florida Rep. Dennis Ross, announced his departure the same morning as Ryan.

But three of the Philadelphia region's Republicans who are walking away said Wednesday that they, like Ryan, had decided to step down for personal reasons, not political ones. They dismissed any political impact Ryan's exit might have, or any symbolism behind his move.

Instead, the lawmakers said they truly believed Ryan wanted to spend more time with his teenage children, noting that he was reluctant to  become speaker to begin with.

"Very few people have any understanding of the level of intensity that a member of Congress, if they're going to do the job right, puts into it," said LoBiondo, of the Atlantic City area. "Almost none of us have any idea of what the magnitude of intensity is to be speaker, second in line to be president."

Costello, of Chester County, recalled telling Ryan recently that he wouldn't seek reelection, and mentioning a desire to spend more time with his kids.

"He said, 'I get it, I get it more than you can understand,'" Costello said. "I don't think that politics played any role in this."

He argued that Ryan remained his party's best messenger, but that the midterm races will center on voters' reactions to Trump, not Ryan.

LoBiondo said the GOP could still hang onto the House, pointing to surprising sports runs this year by the Philadelphia Eagles and 76ers.

"Records are broken all the time," LoBiondo said. "The Sixers: three months ago, did you think they'd win 15 in a row?"