President Joe Biden has signed the Democrats’ landmark climate change and healthcare bill into law.

The hope is it will deliver what he has called the “final piece” of his pared-down domestic agenda, as he aims to boost his party’s standing with voters less than three months before the midterm elections.

The legislation includes the most substantial federal investment in history to fight climate change — some 375 billion dollars over the decade — and would cap prescription drug costs at 2,000 dollars out-of-pocket annually for Medicare recipients.

It also would help an estimated 13 million Americans pay for healthcare insurance by extending subsidies provided during the coronavirus pandemic.

The measure is paid for by new taxes on large companies and stepped-up IRS enforcement of wealthy individuals and entities, with additional funds going to reduce the federal deficit.

In a triumphant signing event at the White House, Mr Biden pointed to the law as proof that democracy — no matter how long or messy the process — can still deliver for voters in America as he road-tested a line he will likely repeat later this fall: “The American people won, and the special interests lost.”

The House on Friday approved the measure on a party-line 220-207 vote. It passed the Senate days earlier with Vice President Kamala Harris breaking a 50-50 tie in that chamber.

“In normal times, getting these bills done would be a huge achievement,” Senate Majority Leader Chuck Schumer said during the White House ceremony.

“But to do it now, with only 50 Democratic votes in the Senate, over an intransigent Republican minority, is nothing short of amazing.”

Mr Biden signed the bill into law during a small ceremony in the State Dining Room of the White House, sandwiched between his return from a six-day beachside holiday in South Carolina and his departure for his home in Wilmington, Delaware.

He plans to hold a larger “celebration” for the legislation on September 6 once lawmakers return to Washington.

The signing caps a spurt of legislative productivity for Mr Biden and Congress, who in three months have approved legislation on veterans’ benefits, the semiconductor industry and gun checks for young buyers.

The president and lawmakers have also responded to Russia’s invasion of Ukraine and overwhelmingly supported Nato membership for Sweden and Finland.

With Mr Biden’s approval rating lagging, Democrats are hoping that the string of successes will jump-start their chances of maintaining control in Washington in the November midterms.

The 79-year-old president aims to restore his own standing with voters as he contemplates a re-election bid.