Washington (AFP) - After 18 months, a possible victory for Joe Biden's social and climate reform legislation seems within reach: Congress on Saturday began debating a revised version of the US president's cornerstone bill, the fruit of numerous compromises with those on his party's right.

Biden, who took office promising big reforms, is calling the bill "a game-changer for working families."

The legislation -- officially known as the Inflation Reduction Act -- includes $370 billion toward ambitious climate goals and $64 billion for health care.

That would make it the largest investment yet in clean energy by the United States, something that Biden has called "historic."

Despite yearly fires and deadly flooding in parts of the country, the climate crisis does not register high on the average household's list of concerns, falling below issues such as inflation or unemployment.

To garner support for their climate initiatives, Democrats sweetened the legislation with tax credits for producers and consumers of wind, solar and nuclear power.

But the package also would make billions of dollars in tax credits available to some of the country's worst polluters to help them in the transition to cleaner energy. That move has been sharply criticized by the party's progressive wing, though most have accepted it as a necessary evil.

Funding would additionally be allocated toward protecting forests from the increasingly extreme wildfire seasons that have ravaged the US West in recent years, a phenomenon scientists say is directly linked to climate change.

Tackling drug prices

The bill additionally tackles exorbitant drug prices for medication such as insulin, in an attempt to ease the immense inequality that exists in US access to health care.

"The anguish of people not being able to pay for medicines that may save their lives will be greatly reduced," Senate Democratic leader Chuck Schumer said.

A major reform in the bill would, for example, force pharmaceutical companies to offer rebates for certain drugs if the prices are rising faster than inflation.

And for the first time, the federal Medicare program would be empowered to directly negotiate the prices of certain drugs with those companies.  

The cost of some medication in the United States can be up to ten times more expensive than in other wealthy nations, a point regularly made by the Biden camp.

The bill also aims to reduce the federal deficit via a minimum corporate tax of 15 percent for all companies with profits exceeding $1 billion.

'To rob American families'

The ambitious spending plan is popular among Americans, according to several polls, but has been strongly denounced by Republicans, who say Biden will stoke record-breaking inflation.

"Democrats have already robbed American families once through inflation," said Republican Senate leader Mitch McConnell, "and now their solution is to rob American families a second time."

But Republicans' tools to block the legislation are limited: because it is a spending bill, Democrats can use a mechanism known as reconciliation to pass it without any votes from across the aisle. 

The Republicans could, however, try to slow the legislative process by presenting amendments during debate.

The Senate is expected to vote on the bill by early next week. After that, it will head to the House of Representatives, where Democrats have a narrow majority.

Biden, seeking a political win with fewer than 100 days before November's midterm elections, is urging Congress to pass it without further delay.