In the midst of a contentious recount of the election results in Florida this past month, Sen. Marco Rubio (R-FL) began tweeting his suspicions that Democrats were trying to game the system, even suggesting that they were producing voters out of thin air in an attempt to flip the race for since-defeated Sen. Bill Nelson (D-FL).

The missives were frequent and often conspiratorial, so much so that several associates of Rubio said they suspected a staffer had to be authoring them under his name.

His deputy chief of staff Dan Holler dismissed the ghost authorship idea to The Daily Beast. “He most certainly is” writing his tweets, he said. But the doubts underscored a wider confusion over the role Rubio’s adopted in the era of Donald Trump.

Just what is the now senior senator from Florida doing? It’s the topic of countless speculation and media ink, including two articles in the Washington Post in just the past few weeks.

His critics, and there are many, see a senator who was once defined by a sunny disposition and principled conservatism now consumed by grievance politics. To them, Rubio was supposed to be the future of the Republican Party, only to become the dutiful sidekick to the man dominating the party’s present.

“They have all disappointed to some degree,” Max Boot, the Republican foreign policy adviser who worked on Rubio’s 2016 presidential campaign, said of the class of GOP senators who took on Trump in that election. “But few have disappointed as much as Rubio has because he has the greatest potential and he could have emerged as a more powerful tribune of a principled conservatism. Instead, he is reading the political winds and trying to make himself into a Trumpian disciple in order to run for president in 2024.”

Rubio’s defenders see progress, not disappointment. The senator may be searching for the right role to play in the Trump era but so is virtually everyone else within the Republican tent. And while he has largely made peace with a man who mocked him mercilessly on the campaign trail, that reparation has come with benefits: a voice at the table, the ability to move certain policies, and, more than anything else, continued relevance politically.

“The way the senator views this is he will work with anyone he can to advance good policy and will try to persuade people and, when appropriate, will make those arguments publicly,” said Holler. “There is authenticity about his concern for the country. He is identifying where the policy gaps are and where Americans don’t feel heard and do feel left behind because federal policy has been poorly implemented and designed. That’s very much where his head is.”

But as content as Rubio may be in his current role, his staff is keenly aware that not everyone else is. And they find the critiques tiresome. Asked about Boot’s criticism directly, Holler refused to engage. “I will send you the tweet I sent on Max and leave it at that.”

Two days later, he did.

Among the current crop of Republican senators, few have such a diametrically different biography from Trump as does Rubio. The president preaches a political vision steeped in fear of immigrants and nostalgia for the past. He never was in electoral politics prior to becoming president and could hardly be called a conservative before deciding to run as a Republican for the White House.

Rubio, by contrast, rose quickly through the ranks of state politics as a new-look conservative. He was a nobody on the national scene when he made his run for federal office; so much so that one former staffer at the National Republican Senatorial Committee said “it was a total courtesy that he was allowed in the building” when he met with officials there to pitch his long-shot Senate run in the 2010 cycle.

He won and quickly became the embodiment of modern Republicanism. In 2013, Rubio put his sizeable political capital behind comprehensive immigration reform. His role was to sell the package to the most hostile audience: conservative media. And he enjoyed some success: Sean Hannity spent the post 2012 election period telling his audience that the Republican Party could only survive if it was less hostile to immigrants.

And then everything fell apart. The Senate’s Gang of Eight bill stalled in the House; Trump burst on the scene in 2015 preaching something entirely different; and Rubio spent months trying to explain why he didn’t support his own bill—not because of some ideological change of heart, he argued, but because political realities dictated that it couldn’t pass.

As the primary progressed, it quickly became apparent who among the two had won the debate within the Republican electorate. Rubio, in a fit of desperation, adopted Trump’s pugilistic approach, mocking the then-front-runner for, among other things, being poorly endowed. But those close to him admit it was a humiliating coda to a disappointing campaign. Rubio left the race, tail tucked between his legs, dubbed forever in the mind of voters as “Little Marco.”

When he chose to run again for his Senate seat there was some expectation that the wounds of the campaign would compel him to not play the role of Trump lackey. Senior Trump White House officials even identified the senator as a potential problem shortly after Election Night in 2016. But they proceeded with cautious optimism that he “would fold hard” on major issues, as one senior administration official said.

“ The president has come to view his former political foe as a supplicant more than a competitor, and a helpful one at that. ”

They turned out to be correct. Rubio has regularly expressed disappointment with a path Trump has taken, only to find his way to get to yes. He hinted that he might not support Trump’s Secretary of State nominee Rex Tillerson, because of Tillerson’s ties to Russia, before voting for confirmation. He held out support for Trump’s pick to lead NASA, on grounds that Jim Bridenstine had virtually no experience in the field, before offering his support. He embraced Trump’s immigration policies, including the construction of a border wall, and backed the president’s massive tax cut, even after hinting that he found it too tilted to corporations.

But he also extracted some scores along the way. White House officials give Rubio credit for getting an expansion of the child tax credit in the tax bill’s final language precisely by keeping his vote in play.

“To be quite candid there was division in the White House about whether that was good policy or not but he was determined to keep fighting for that,” said Marc Short, who briefly advised the Rubio campaign and was until recently Trump’s White House director of legislative affairs.

He also has, according to administration officials, increasingly become a senator the president and his team consults on matters of foreign policy. Rubio has long been a hardliner when it comes to the Castro regime in Cuba and the Maduro government in Venezuela, even arguing that the latter deserves to be added to the State Department’s terror sponsorship list—positions Trump’s echoed. He also cheered the president’s decision to withdraw the U.S. from the Iran nuclear agreement and has found a way to merge his China skepticism and free-market instincts into approval of Trump’s tough trade policies.

One former Rubio aide said the Senator was seeking to curry favor with Trump precisely to influence him on foreign policy, even “if it means that he is willing to be a surrogate on some of the other aspects of the president’s agenda.”

“Everyone knows the president has a short memory on these things. So if you want to continue to be a voice on them and you want to continue to have influence on these issues, you need to continue to curry favor,” the former aide said. “If you want to continue to be a voice in foreign policy like Marco does, then you need to continue to ensure that the president thinks of you as a voice to look toward on these issues. Because everyone knows that the president doesn’t have this depth of foreign policy knowledge to count on.”

For its part, Trumpworld seems increasingly pleased with the role Rubio’s been playing. Matt Schlapp, a Trump surrogate and chair of the American Conservative Union, whose wife Mercedes Schlapp works in the Trump White House as a senior official, said he was thrilled that Rubio has stayed in line, and believes there is still a bright future for Rubio as a national figure, during and after the Trump years.

“Do I think Sen. Rubio and President Trump have a bromance? I don’t know,” he said. “But I do know that Sen. Rubio wants to see America project strength… and wants to make sure our national security functions are well-funded. He wants to fight the war against Islamic extremism... and protect Israel. On so many fronts there are commonalities.”

White House spokespeople did not have a comment for this story as of press time. But privately, the president has come to view his former political foe as a supplicant more than a competitor, and a helpful one at that. One former West Wing official recalled Trump privately praising Rubio for being “so right” in March, when he declared that leakers who disclose national-security secrets to reporters should resign.

“I don’t call him Little Marco anymore” Trump said, with a smirk, during a private conversation earlier this year, according to a source close to the president.

Rubio is hardly the only Republican senator whose performance in the Trump era has sparked rounds of disdain among critics of the president. Jeff Flake (R-AZ) and Bob Corker (R-TN) are often mocked for pushing back against Trump in the most ineffectual of manners. Susan Collins (R-ME) is ridiculed for the ease in which she rolls over. Rand Paul (R-KY) is viewed as abandoning his principles and Lindsey Graham (R-SC) is questioned for having any. But few, if any, generate such nostalgia-dripped lament as Rubio.

“The story of Rubio right now is kind of grim because it was once filled with so much hope,” said Rory Cooper, a longtime Republican operative.

Much of what drives the Rubio commentary is the lingering sense that, unlike the others, he is not a true believer in Trumpism so much as an opportunistic one. It’s the go-to explanation for why the senator can pen an op-ed in the Wall Street Journal declaring the president to be right about the notion of American “nationalism” and then, days later, lament that Trump’s nationalism doesn’t include supporting international human rights.

But there’s also a steady belief that Rubio is doing this all with an eye for being in the right place when Trumpism ends or falters. This past year, the senator hired Heritage Action’s then-CEO Michael Needham to be his chief of staff. Later he brought on Needham’s Heritage colleague, Holler. Bare-knuckled political operatives who spent years knocking GOP lawmakers for their lack of conservatism, Needham and Holler seemed like an odd fit for the man who ended up being the mainstream alternative to Trump in 2016. And there’s been speculation from some Rubio critics that they’ve pushed him in his current, more outwardly confrontational direction.

“That would be horribly untrue,” said Holler.

But absent the men-behind-the-curtain explanation for Rubio’s recent conduct, there is another, perhaps simpler, alternative. As one Republican strategist put it, Rubio is a straight movement-conservative at a time when it was difficult to figure out what conservatism means. “Needham is indicative of where he has decided to go,” the strategist said. “It is laying the groundwork on being on the true conservative side even if that’s not exactly where the party is going right now.”

Rubio is certainly acting like a man hoping to reclaim conservatism, even if it’s in a slightly tinkered, more Trumpian image. One day he delivers a speech at the Heritage Foundation outlining the need to expand the earned-income tax credit and reduce and streamline food stamp benefits. The next he is spreading viral videos on Twitter reportedly showing Florida election workers moving ballots in the middle of the night.

Recently, he told the Washington Post that he wanted to build a sustainable governing coalition with voters brought into the political process by Trump and those who had left the Republican Party because of him. The question is whether he’s actually able to do it.

“I don’t think it is inconsistent to say he has a bright future, is a man of big ideas, and is a savvy politician and can also work with the Trump administration,” insisted Short. “I don’t think they’re conflicting.”

—Andrew Desiderio contributed reporting.