But who is partly behind this surprise agreement? None other than Larry Summers, the former treasury secretary and well-known critic of Biden who was reportedly enlisted by Senate Democrats to gain Manchin’s support. 

“The two men spoke this week, and Manchin listened as Summers talked in detail about why Democrats’ proposed economic package — including its energy provisions — would not lead to higher prices,” according to The Washington Post, which cites sources familiar with the matter. 

In the past, Summers has criticized Biden’s handling of inflation, specifically Biden’s stressing of Putin as the cause. Rather, Summers told Bloomberg Television that the surge of inflation is the result of an overheated economy. He’s argued Biden’s pandemic relief plan and increasing demand are the main cause for the current inflationary spike. 

But on Wednesday, in response to the announcement about Manchin’s new support of the bill, Summers shared his approval of Biden’s bill on Twitter. 

“Great budget deal announced today,” he wrote. “This will mean progress on inflation, economic growth, tax fairness, inequality, and climate change.

Manchin’s support for the bill follows his previous opposition to Biden’s Build Back Better Act. Although the current version is much slimmer than the president’s original version, it still marks a major reversal by Manchin, who had earlier said the legislation would negatively affect the nation’s already record-high inflation. 

Summers, however, disagreed that the bill could increase inflation. 

Manchin is considered to be one of the most conservative Democrats in Congress. In May, in effort to codify the right to abortion into law, he joined Senate Republicans in voting against the Women’s Health Protection Act, tanking the legislation. He was the only Senate Democrat to vote no. 

Passage of the Inflation Reduction Act of 2022, which would raise $739 billion in revenue and invest $433 billion in energy security and climate change along with extending the Affordable Care Act, would be a huge victory for both Biden and House Democrats. 

Whether it will pass could come down to Sen. Kyrsten Sinema (D-Ariz.), who hasn’t indicated whether she would support it, and has previously opposed raising taxes on high-income earners. 

To be approved in the Senate, Democrats hope to use a budget process known as reconciliation, which would allow the bill to pass with 50 votes, meaning all Senate Democrats would need to support the bill for it to move to the House.