Most powerful man you've never heard of: Meet the boat-dwelling, gun-toting Democrat with the future of America in his hands

The fate of Joe Biden’s massive spending plans, and the future of America, may be decided on an innocuous looking houseboat several miles away from the US Capitol.

It belongs to Joe Manchin, the Democrat senator from West Virginia, who has emerged as the key vote needed to secure the passage through Congress of Mr Biden's multi-trillion dollar proposals.

The Senate is divided 50-50 between Democrats and Republicans, with Vice President Kamala Harris holding a casting vote.

Republicans are unified in their opposition. So it all hangs on Mr Manchin, the most conservative Democrat senator. He is now widely referred to as "the second most powerful 'Joe' in Washington".

Mr Manchin is known for his fiscal prudence, and he is having serious doubts.

After hearing Mr Biden's speech to Congress on Wednesday, during which he took copious notes, he said: "It’s a lot of money. A LOT of money. That makes you very uncomfortable."

Mr Manchin is an outlier in the Democratic Party, and in Washington. He dislikes the capital city so much that in his decade there he has refused to buy or rent a home.

Instead, he lives and works on a 40ft boat, which cost far less than any property on land.

His water-based residence has emerged as a convivial getaway where Democrats and Republicans can mingle privately away from the toxic atmosphere of Congress.

He takes political friends and foes on evening cruises along the Potomac River, serving pizza and beer, and his boat has been dubbed the "flagship of the centrist Navy".

While Mr Biden promised bipartisanship, in practice it is Mr Manchin who is actually pursuing it. Republicans are currently talking, not to the White House, but to "the other Joe".

Read more: Douglas Murray: Cuddly old Joe Biden is just as divisive as Donald Trump ever was

Even Ted Cruz, the firebrand Republican senator, has been aboard. Susan Collins, the moderate Republican from Maine, is a frequent guest, as is the Democrat Senate leader Chuck Schumer.

"He [Mr Manchin] suddenly becomes the most powerful person in this place [the Senate]. He’s the 50th vote on everything," Democrat senator Chris Coons, a close friend of Mr Biden, said recently.

Mr Manchin is currently talking to Republicans about their alternative $568 billion infrastructure proposal, which is one quarter the size of Mr Biden's gargantuan $2.3 trillion plan.

Last week, Mr Manchin met with Donald Trump ally Senator Lindsey Graham. He has also spoken to Republican Senate leader Mitch McConnell, which alarmed some Democrats.

Mr Biden's infrastructure bill, together with a $1.8 trillion American Families Plan focused on education and childcare, and his already passed $1.9 trillion coronavirus relief package, represent the biggest expansion of the US government since the 1960s.

However, Mr Manchin has already indicated he will not back a rise in corporation tax from 21 per cent to 28 per cent to pay for some of it. His limit is 25 per cent.

He is also said to have concerns over the president's plan to double capital gains tax to 43.4 per cent on investors making over $1 million.

Mr Manchin, whose state of West Virginia is the second-largest coal producer in the nation, may also wield a veto on some of Mr Biden's more progressive climate policy. This risks blunting the president's leverage on the global stage where he is calling on world leaders to commit to major cuts to carbon emissions.

Mr Manchin grew up in Farmington, West Virginia, a small coal town.

He worked in a grocery shop and then went to West Virginia University on an American Football scholarship as a star quarterback, before a devastating knee injury.

Then he worked his way up in local politics, ultimately becoming a popular governor of the state.

Mr Trump won West Virginia by staggering landslides of 42 points in 2016, and 39 points in 2020.

All the state's other senior politicians are Republicans. But still West Virginians keep on voting for one Democrat - the 74-year-old Mr Manchin.

In election campaign adverts Mr Manchin likes to use a rifle to shoot holes in pieces of legislation he doesn't like.

While he stands with Democrats on most issues including Obamacare, he backed Mr Trump's immigration policies, strongly supports the Second Amendment, and opposes Democrat plans for a $15 minimum wage.

After the president's speech, he said: "We can't overreach to the point we stymie investments and growth for 2022, 2023, 2024 and beyond. How much more debt? We're almost $28.3 trillion [in debt].

"That's not sustainable in anybody's book. We’re relying on Uncle Sam to do everything."

Mr Manchin calls himself a "West Virginia Democrat not a Washington Democrat" and frequently declares that "my worst day as West Virginia governor was better than my best day as a Washington senator".

When he eventually retires he wants to drive his boat back home to West Virginia.

Before that the White House is desperately hoping he finds his way home to the Democratic Party.

Read more: Biden's walking a tightrope between big spending and the stretch of the public purse