Three candidates have either announced or seem poised to announce bids to challenge Donald Trump in the 2020 Republican presidential primary.

But for many who are itching for a strong conservative or libertarian alternative to the president, the hope is for a fourth to emerge.

Rep. Justin Amash’s political future has been the subject of intense fascination and interest in Republican circles these days. After his call to impeach Trump and his subsequent exit from the GOP, the libertarian congressman from Michigan has attracted tons of buzz over a possible run for president as a third-party candidate.

Amash’s plans remain opaque. Publicly, he insists he’s running for re-election to his House seat until he says otherwise. Privately, he’s told supporters the same thing. And while those people believe Amash is actively considering a presidential bid, his political inner circle is so tight-knit about the possibility that allies have little idea what the congressman is actually planning.

That cone of silence has fueled speculation that Amash will join former Govs. Bill Weld and former Rep. Joe Walsh in formally challenging President Trump. And it has supercharged outside efforts to get him in the race. Several officials in the Libertarian Party, which would be the most logical vehicle for an Amash presidential run, told The Daily Beast they have been reaching out to the congressman’s camp to indicate that he’d have strong support among the activists who decide the party’s presidential nomination.

Those who know Amash say he may be waiting on two things before making a decision: a clearer sense of Libertarian Party support, and a clearer statement of plans from another rumored Trump challenger: his former House colleague Mark Sanford. The South Carolina Republican, who served as governor and a member of Congress before losing his seat last cycle, has not yet officially launched a bid but is considered likely to challenge Trump in the GOP primary.

The Daily Beast spoke with six people who either know Amash personally or have worked with him, three of whom requested anonymity to speak candidly about what his plans may be. One of them said that the congressman is almost certainly waiting to see if Sanford will run, and that he would not run himself if his old friend were to get in the race.

But in an interview with The Daily Beast last week, Sanford himself said there would be plenty of room for both of them to run.

“If I was taking one bite at the apple and he was taking another, I don’t think it hurts me,” said Sanford, who said he hadn’t spoken with Amash recently about his plans. “It enhances the collective ability to get a message out relative to a sitting president.” He added that if Amash were to run, “I’d ask he would count me in as a supporter.”

Unlike other Trump challengers, Amash would not be competing against him in a primary. The damage he could inflict, instead, would come in a general election contest, where a conservative alternative to the sitting president could, potentially, pull away some Republican votes in key states. But there is a sense that he will need to announce soon in order to make a bid count—most likely by the end of the year.

“At some point in time,” said a source with close knowledge of libertarian politics, “Justin’s going to have to shit or get off the pot.”

In the meantime, Amash is clearly benefiting from the aura of mystery around his current plans, said Liz Mair, a GOP strategist and Trump critic with libertarian views. “Sanford sends out press releases saying he’s going to New Hampshire—no one knows if he’s running or not, but they know he’s doing some shit so he could,” she told The Daily Beast. “No one knows what Amash is doing. People like a mystery.”

Amash’s House campaign did not return requests for comment.

In the world of Libertarian Party politics, rumors have been flying in recent weeks about informal efforts by Amash supporters to gauge interest among party activists in an Amash presidential campaign.

Libertarians award their presidential nomination at a convention and not through a traditional state primary process, which tends to reward candidates who hustle to court the devoted Libertarians that make up the base of convention delegates. A Libertarian Party source told The Daily Beast that activists close to the Amash camp have reached out to state-level party officials to feel out an Amash bid and to learn more about the party's presidential nomination process.

Traditionally, there has been suspicion of Republicans who cross over to run as Libertarians, but the party’s last two presidential standard-bearers—former Gov. Gary Johnson and former congressman Bob Barr—were once formal Republican Party officials themselves. And thanks to Amash’s high profile and ideological pedigree, some in the Libertarian Party anticipate that the congressman could pick up significant support among the party’s rank-and-file shortly after launching a campaign.

One source who knows Amash told The Daily Beast that the congressman is likely waiting to see if the Libertarian nomination would be a lock for him should he make a bid. “If I were to guess where he is right now, I'd say that he's trying to make sure that he would walk into the Libertarian nomination without having to fight for it,” the source said. “His worst case scenario is, he bows out of a congressional fight only to lose the Libertarian nomination.”

Nicholas Sarwark, the chair of the national Libertarian Party’s executive committee, said he is not personally urging Amash to get in the race, but he had spoken with him in the last month.

“I made sure he knows what kind of support he’ll get,” Sarwark told The Daily Beast. “I have a good sense of the delegates around the country, where their heads are at, and they’re positive about him getting in. He would have at least that level of support and help in seeking the nomination.”

And Amash would at least have the well wishes of Johnson, the Libertarian Party’s two-time nominee, who in 2016 pulled a higher share of the national popular vote—3.28 percent—than any candidate in Libertarian Party history.

“It’d be wonderful if he ran!!” the former New Mexico governor said in a text message to The Daily Beast. “I think he is terrific.”

But two sources who know Amash said there’s frustration among allies that he has not built the kind of political operation that would set himself up for a successful presidential campaign.

“His main political operation is basically his family,” one source said. “He's got trust issues… If he had people that he believed would help him evaluate it on the terms he wants to evaluate it on, then I think he would bring them in. But everyone has a different agenda and most are not about advancing Justin Amash's career or influence over the system.”

As Amash weighs the pros and cons of a presidential bid, he must also keep an eye on his future in the House. Newly independent of any party organization, he faces a squeeze from both sides in his home district: Peter Meijer, an Army veteran and a member of the prominent Michigan retail business family, is leading a crowded Republican primary field. The eventual winner of that contest is likely to earn substantial backing from national GOP groups, not least because Trump’s political operation has let it be known that they want to see Amash gone. And the powerful DeVos clan, based in Amash’s district, has made it clear their political largesse will no longer fuel the congressman’s House campaigns as it has before.

A squabble between Amash and the Trump-affiliated factions in the 3rd District could leave an opening for a Democratic candidate, if a small one. After winning re-election in 2016 by 22 points, Amash defeated Democratic candidate Cathy Albro by 11 points in 2018. Albro is running again in 2020, as is a Democratic newcomer, attorney Hillary Scholten.

At the crux of Amash’s decision is whether he wants to trade a congressional campaign he could possibly lose for a presidential campaign he is virtually guaranteed to lose. While some around Amash say he would only run for president if he believes he would win—a long-shot scenario, to put it generously—others, like Sanford, think he conceives of victory differently.

“If you follow his votes in the House, what you’d say is, he’s motivated by an internal compass that’s based on belief,” Sanford said. “I can’t imagine him changing gears to say, oh, I’ll only look at something like this in an electoral sense.”

Sanford did nod to the chance that if Amash were to run a campaign focused on a handful of states that he could win himself or at least deny Trump, he could possibly ensure the president’s defeat to a Democrat.

But allies say the congressman, a vocal critic of both parties, will probably find the eventual Democratic nominee deeply flawed too—making it unlikely he’d savor any part in bringing about the inauguration of a President Elizabeth Warren or Kamala Harris.

“He would definitely not be doing it to be a spoiler,” a source said. “But I also don’t think that winning is the only consideration. Putting voice to certain concepts of limited government, what the Constitution says, I think he’d find enough value in that to be worth it.”

—with reporting from Betsy Woodruff