Joe Biden calls him “Jo-Jo”, an affectionate nickname for the West Virginia senator who, at critical moments during his presidency, has been the Joe holding all the cards.

And this week Joe Manchin, a lonely coal state Democrat who has repeatedly stood in the way of the president’s most ambitious legislative aspirations, derailed weeks of negotiations in pursuit of a deal on a scaled-back version of Biden’s economic agenda that would win his support.

With control of Congress at stake, Democrats had hoped to reach a deal that fulfilled their campaign promises to combat global warming and expand the social safety net by the end of the month, giving lawmakers a legislative achievement to campaign on in the fall. But Manchin’s latest gambit all but ensured Democrats’ biggest ambitions would go unrealized.

“Rage keeps me from tears,” Senator Ed Markey, a Democrat from Massachusetts and sponsor of the Green New Deal, wrote on Twitter late Thursday, as news broke of Manchin’s opposition. “Resolve keeps me from despair.”

In a private discussion on Thursday, Manchin told Democratic leaders that he could not support a bill that contains new spending to combat climate change or raises taxes on wealthy Americans and corporations.

By Friday morning, he had clarified his position. It was “not prudent” for Democrats to approve a major spending package while Americans faced painfully high costs for food, fuel and rent, the 74-year-old said in a radio interview.

“Inflation is wreaking havoc on everybody’s life,” Manchin told the host, Hoppy Kercheval.

But he offered an ultimatum: Democrats could accept a narrow deal now or try to pass a larger plan later, if the economic forecast improves.

With his economic agenda in peril, Biden urged Democrats in Congress to accept what they could get done immediately to lower healthcare costs and vowed to act unilaterally on the climate crisis.

The demands came at an inauspicious moment for the party’s leaders: the Senate majority leader, Chuck Schumer, who has been leading the fragile talks with Manchin, is stuck quarantining at home in Brooklyn after a Covid diagnosis while Biden was on a high-stakes trip to the Middle East. The president outlined his preferred course of action in a statement sent after he held a controversial meeting with the Saudi leader, Crown Prince Mohammed bin Salman, during which rising fuel prices and oil production were top of the agenda.

“Let me be clear: if the Senate will not move to tackle the climate crisis and strengthen our domestic clean energy industry, I will take strong executive action to meet this moment,” he said.

It was in effect an acknowledgment that after more than a year of tortuous negotiations, Manchin could not be moved, not by activists, not by his colleagues, and not even by the president of the United States.

“At some point you have to take the man at his word that he is not going to do that which he says he is not going to do,” said Christopher Regan, a former vice-chair of the West Virginia Democratic party who worked with Manchin.

In a Senate divided evenly between the parties, any one Democrat could play king or queenmaker. But no one has done so more boldly or more frequently than Manchin.

Fiscally conscious and socially conservative, Manchin is glaringly out of step with today’s Democratic party – and he knows it. At one point, he even offered to leave the Democratic party if his colleagues thought he’d become too much of an “embarrassment” – an offer he said they roundly rejected.

Manchin comes from a political family in West Virginia, part of a legacy of Industrial-era Democrats who formed the party’s blue-collar base. Once one of the most reliably Democratic states, West Virginia began to turn sharply against the party, as the party bled support from white, working-class voters. In 2020, every single county in West Virginia voted for Donald Trump.

Manchin, who began his career in state politics and served as governor, has so far defied the state’s lurch to the right. He was elected to the Senate in 2010, two years after Biden left to become vice-president, and won re-election in 2018.

His victory helped Democrats build their fragile majority, with vice-president Kamala Harris serving as the 51st and tie-breaking vote.

Reaching consensus hasn’t been easy. Manchin’s vote has been critical to approving Biden’s judicial nominees, and he ultimately signed off on the president’s massive Covid relief legislation over unanimous Republican opposition.

But Manchin has joined Republicans to imperil some of Biden’s nominations, including Neera Tanden, who the president tapped to run the Office of Management and Budget and Sarah Bloom Raskin, who he chose to serve on the Federal Reserve. Neither were confirmed.

Manchin is also a staunch defender of the filibuster, a Senate rule requiring 60 votes to advance legislation which he insists encourages consensus in a deeply tribal chamber. Even when Republicans tested that view by obstructing a voting rights bill he crafted as a compromise solution to the matter, Manchin, joined by Democratic senator Kyrsten Sinema of Arizona, remained firm.

It’s a stance that puts the Democrats at odds with Biden, an avowed institutional who has nevertheless endorsed changing the filibuster rules to pass votings right legislation and abortion protections.

In recent weeks, Biden has made repeated reference to their opposition, telling Democrats “we need two more senators” to break the current gridlock that has paralyzed much of his agenda.

Nothing has angered Democrats more than Manchin’s opposition to Biden’s economic agenda.

Known as Build Back Better, it began with New Deal-sized ambitions that, even at its slimmest, would still have dramatically expanded the social safety net and invested in critical efforts to lower carbon emissions.

After months of frantically trimming and tailoring the legislation to meet Manchin’s demands, the senator abruptly drove a stake through the heart of the Democrats’ plan. Adding insult to injury, in the eyes of his colleagues, he announced his decision during an interview on Fox News. The revelation was so unexpected, it startled the host, Bret Baier, who asked for clarity: “You’re done? This is a no?”

He was done.

Talks on a stripped-down version of the bill began quietly earlier this year. Democratic leaders and the White House sought to keep expectations low even as the party’s demoralized supporters demanded action. Manchin says he’s open to a plan that would lower the cost of prescription drugs and extend Affordable Care Act subsidies set to lapse at the end of the year.

Manchin’s approach has infuriated Democrats, particularly progressives who feel he has negotiated in bad faith, raising hopes before dashing them right when a deal seems within reach.

“What he makes clear over and over again is that he can’t close the deal, and that you can’t trust what he says,” Washington congresswoman Pramila Jayapal, chair of the Congressional Progressive Caucus, told reporters on Friday.

Manchin, apparently impervious to liberal pressure, argues that it’s him who has been consistent from the outset, voicing concern over rising inflation even when the president was arguing, wrongly, that it would prove “transitory”. New data showing that prices rose by an astonishing 9.1% in June prompted Manchin’s apparent reversal on the tax and climate provisions of the Democrats’ plan. In a statement, Manchin warned that new spending proposals risked inflaming inflation, which he called a “clear and present danger to our economy”.

Activists in West Virginia and Washington have tried to cajole him with protests, sit-ins and ad campaigns to . Once a group of climate advocates in kayaks held signs that read “don’t sink our bill” during a “flotilla” protest outside his houseboat, Almost Heaven, where he lives when he is in Washington. Even Senator Bernie Sanders weighed in, with an op-ed in a West Virginia newspaper that drew Manchin’s ire.

The West Virginian has always argued that he votes in the interest of his state, historically poor and hurt by the coal industry’s decline.

But critics are skeptical, particularly when it comes to his position on climate legislation. Manchin is the Senate’s top recipient of campaign contributions from the oil and gas industry and has made millions from his family’s coal firm.

“Senators have told me and others that negotiating with Joe Manchin is like negotiating with an Etch-a-Sketch,” Norm Ornstein, an emeritus scholar at the American Enterprise Institute, said of Manchin’s opposition. “It appears to be a coal-powered Etch-a-Sketch.”

In the radio interview on Friday, Manchin, who chairs the Senate energy and natural resources committee, indicated he might be interested in additional action on the climate crisis, if inflation begins to ease this summer.

Whether Manchin and Biden can reach an agreement on the president’s biggest legislative priority before the November election will likely have profound implications for their party, but also, potentially, for the senator’s own political future.

“There’s no friends for [Manchin] after this,” Regan, who worked in West Virginia Democratic politics, said. “He’s completely alienated the Democratic Party that supported him all the time and he’s nowhere near right-wing enough for the West Virginia Republican Party.”