Paul Ryan's move to quash speculation about his rumored presidential ambitions has forced establishment Republicans to reckon with the possibility that their standard-bearer will likely be either a nativist, divisive billionaire or an ideological warrior who's despised by most of his Senate colleagues.

For elites who began this election cycle hoping that a more moderate Republican would carry their torch all the way to the White House, Ryan's move fueled a fresh round of indecision and despair over front-runner Donald Trump and Sen. Ted Cruz, who is holding steady at second place.

"We've got so many problems-there are a myriad of problems. None of this is going to turn out well for the Republican Party," Sen. John McCain of Arizona, the party's 2008 nominee, told reporters in Washington Tuesday.

"I am at a loss. OK? I do not know what's going to happen. I just don't see that a lot of it's going to turn out well. Because there are too many divisions within our party," he said.

Ryan, a Wisconsin Republican who just months ago managed to unite the party around his ascent to House speaker, isn't the only GOP wildcard being floated.

In recent days, a shadowy group of billionaires has been trying to draft retired U.S. Marine Corps Gen. James Mattis, according to The Daily Beast. Washington Post columnist David Ignatius added four other names to the potential Republican mix: Gen. Stanley McChrystal, Adm. Mike Mullen, Gen. David Petraeus and former House Intelligence Committee Chairman Mike Rogers.

None of these candidates are likely to actually enter the race, let alone overtake Trump or Cruz, who has steadily held second place in delegate count. Ryan, who also serves as chairman of the GOP Convention, seemed to agree.

"Let me speak directly to the delegates on this," Ryan told reporters Tuesday at the Republican National Committee's headquarters in Washington. "If no candidate has a majority on the first ballot, I believe you should only choose a person who actually participated in the primary."

Trump leads with 743 delegates, ahead of Cruz with 545 and Ohio Governor John Kasich far behind with 143, according to an Associated Press tally. If no candidate reaches 1,237, the nomination can be contested at the July convention. Fourteen other Republicans have run for president this cycle and dropped out after failing to attract sufficient support.

Sen. Jeff Sessions of Alabama, who has endorsed Trump and serves as a chief foreign policy adviser, said it would be "problematic, for sure" if Republicans nominated someone who had not faced voters this year.

"I think the right thing is for the nominee to come out of the convention, out of the candidates who've won delegates," Sessions told Bloomberg Politics.

"I'm not naive in thinking that [Kasich] would have the votes, but I think that he should be in the mix and it's very important for the Republicans to carry Ohio," Sen. James Inhofe of Oklahoma said. "Who knows, he may end up-even though he would deny it-he may end up being an attractive vice presidential running mate."

Sen. Rob Portman of Ohio said he would "love to see John [Kasich] end up being our nominee and the best president." As for whether it'd be a bad idea to nominate an outside candidate, Portman said, "I think, as I've said repeatedly, we've got to let the process work, which means the delegates make the decision."

The next Republican contest is in New York on April 19, and a swath of other Northeastern states one week later. Polls give Trump a strong advantage over Cruz in New York and Pennsylvania, but the billionaire still risks falling short of the 1,237 delegate threshold.

Trump lashed out at Republican National Committee Chair Reince Priebus in an interview with The Hill on Tuesday, calling the nominating system "a disgrace for the party. And Reince Priebus should be ashamed of himself. He should be ashamed of himself because he knows what's going on."

Sean Spicer, the chief strategist and spokesman for the RNC, responded by reminding Trump of long-standing rules. "Understanding the delegate selection and allocation is a basic part of the campaign," he said in a statement to The Hill.

Despite attempts by senior Republicans and the Trump campaign to clarify the process, questions persist.

"If anyone tells you that they would anticipate something happening, be careful because we won't know what the rules are until a week before the convention," Inhofe said.

Sen. Ron Johnson of Wisconsin said the endgame for Republicans remains shrouded in mystery even after Ryan's announcement.

"Nobody can predict this process," he said.