Tolong jelaskan mengenai Latar belakang dari Undang-Undang Build Back Better

Before the bill was spun off from the American Jobs Plan (AJP), on April 5, 2021, Senator Joe Manchin proposed raising the corporate tax rate from 21% to 25%, instead of the 28% Biden originally called for. On May 25, Republican senators Pat Toomey and Roger Wicker indicated a lack of support within their caucus to change aspects of the 2017 tax act, and suggested repurposing unspent COVID-19 relief funds. On May 28, Biden released details of a $6 trillion budget proposal for the fiscal year of 2022, which would raise taxes on corporations and millionaires to pay for both the AJP and the American Families Plan (AFP) over 15 years. On June 3, White House press secretary Jen Psaki announced a tweaked AJP proposal that would not increase taxes on corporations, in exchange for closing loopholes and requiring them to pay at least 15%. On June 5, finance ministers from Group of Seven announced that they would support a global 15% corporate tax minimum.

On May 17, seven Democrats on the House Ways and Means Committee signed a letter to the president asking him to prioritize enhanced unemployment insurance (UI) and direct payments (in the style of those included in response to  and the related recession) in the AFP. The letter cited Biden's promise to include the former adjusted to "economic conditions", but further that the latter also "served as [a lifeline] to families and workers that have had their lives upended by the pandemic". Previously, on March 31, 21 Senate Democrats sent Biden a letter in favor of further stimulus payments and UI, and in April, the Economic Security Project reported that two additional direct payments could keep 12 million Americans out of poverty.

On May 28, Senate Parliamentarian Elizabeth MacDonough indicated that the current rules dictate that the reconciliation process should not be used more than once during a fiscal year. A majority in the Senate Budget Committee would be needed to change this. On June 3, Senator Manchin advocated against using reconciliation, though other Democrats supported it. On June 16, Senate Majority Leader Charles Schumer met with the Democratic members of the Senate Budget Committee to discuss the option of passing a budget resolution using reconciliation. Democrats were reportedly considering such a bill around $6 trillion. In late June, Manchin said he was open to adjusting the 2017 tax bill and stated his support for a $2 trillion reconciliation bill.

On June 24, a bipartisan group met with the president and reached a $1.2 trillion bipartisan deal focusing on physical infrastructure (such as roads, bridges, railways, water, sewage, broadband, and electric vehicles). Biden stipulated that a separate "human infrastructure" bill (such as child care, home care, and climate change) must also pass, whether through bipartisanship or reconciliation, but later walked back this position. White House officials stated on July 7 that legislative text was nearing completion. On July 14, the Senate Energy and Natural Resources Committee advanced an energy bill expected to be included in the bipartisan package. House Speaker Nancy Pelosi similarly stated that the House would not vote on the physical infrastructure bill until the larger bill passes in the Senate, but later walked back this position as well, as the physical infrastructure package passed the House on November 5 and was signed into law before the larger bill had received a vote.