A raft of retirements, difficulty recruiting candidates and President Donald Trump's continuing pattern of throwing his party off message have prompted new alarm among Republicans that they could be facing a Democratic electoral wave in November.

The concern has grown so acute that Trump received what one congressional aide described as a "sobering" slide presentation about the difficult midterm landscape at Camp David a week ago, leading the president to pledge a robust schedule of fundraising and campaign travel in the coming months, White House officials said.

But the trends have continued, and perhaps worsened, since that briefing, with two more prominent Republican House members announcing plans to retire from vulnerable seats and a would-be recruit begging off a Senate challenge to Democrat Heidi Heitkamp of North Dakota despite pressure from Trump to run.

And by the end of the week, many Republicans were scrambling to distance themselves from the president's reported vulgar comments during an Oval Office meeting with lawmakers about immigration policy. Rep. Mia Love, R-Utah, a rising star in the party who faces a strong Democratic challenge this year, quickly denounced Trump for apparently denigrating Haiti, her parents' birthplace, during the Oval Office discussion.

"The president must apologize to both the American people and the nations he so wantonly maligned," Love demanded — creating a model, perhaps, for Republicans in competitive races to try to separate from Trump.

In the Camp David presentation, House Majority Leader Kevin McCarthy described scenarios to the president ranging from a bloodbath where Republicans lost the House "and lost it big," in the words of one official, to an outcome in which they keep control while losing some seats.

McCarthy outlined trends over recent decades for parties in power and spotlighted vulnerable GOP seats where Hillary Clinton won in 2016. Eight years ago, before the 2010 midterms swept the GOP to power, he had drafted a similar presentation with the opposite message for his party.

Republicans hold the advantage of a historically favorable electoral map, with more House seats than ever benefiting from GOP-friendly redistricting and a Senate landscape that puts 26 Democratic seats in play, including 10 states that Trump won in 2016, and only eight Republican seats.

But other indicators are clearly flashing GOP warning signs. Democrats have benefited from significant recruitment advantages — there are at least a half dozen former Army Rangers and Navy SEALs running as Democrats this year — as Republicans struggle to persuade incumbents to run for re-election.

At least 29 House seats held by Republicans will be open in November following announced retirements, a greater number for the majority party than in each of the past three midterms when control of Congress flipped.

The president's own job approval, a traditional harbinger of his party's midterm performance, is at record lows as he approaches a year in office, according to Gallup. Polls asking which party Americans want to see control Congress in 2019 show a double-digit advantage for Democrats.

"When the wave comes, it's always underestimated in the polls," said a conservative political strategist who has met with GOP candidates. "That is the reason that Republicans are ducking for cover."

Amid the onslaught, GOP strategists say they continue to pin their electoral hopes on the nation's still-rising economic indicators, the potential effects of the new tax law and Trump's ability to rally the conservative base.