Case Study 1 — A Bipartisan Accomplishment: The Bipartisan Infrastructure Law (2021)

What it was

On November 15, 2021, President Joe Biden signed into law the Infrastructure Investment and Jobs Act (IIJA), often called the Bipartisan Infrastructure Law (BIL). The bill provided roughly $1.2 trillion in federal infrastructure spending — about $550 billion of which was new spending on top of baseline reauthorizations — over five years. Funding categories included roads and bridges ($110 billion in new money), public transit ($39 billion), passenger and freight rail ($66 billion), broadband ($65 billion), water systems ($55 billion), the electric grid ($65 billion), electric vehicle charging ($7.5 billion), Western water infrastructure ($8.3 billion), and various other categories.

It was a substantively significant law. It was also a politically significant law, because in a Congress consumed by partisan deadlock, it passed with substantial cross-aisle support. The Senate vote on August 10, 2021, was 69–30, with 19 Republican senators joining all 50 Democrats. The House vote, after much delay and intra-party drama, was 228–206 on November 5, 2021, with 13 Republicans joining 215 Democrats (and 6 Democrats voting against, mostly on grounds the package was insufficiently linked to the larger Build Back Better social-spending bill).

For a bill of its size, in a Congress this polarized, the IIJA is the most notable bipartisan legislative achievement of the 2021–24 period. Examining how it happened tells us something important about what Congress can still do.

How it happened

The Senate phase: the G10/G20 negotiation

The bill's origins lie in the Problem Solvers Caucus and a small Senate bipartisan working group that emerged in early 2021. The Biden administration had proposed an expansive infrastructure package in March (the "American Jobs Plan"), but it was clear from the outset that no version of that plan would clear a Senate filibuster (60 votes required). Some Democrats argued for using the budget reconciliation process — which requires only a simple majority — to enact infrastructure on a partisan basis. Others, including Senators Joe Manchin (D-WV) and Kyrsten Sinema (D-AZ, then), insisted on attempting bipartisanship first.

A bipartisan group of senators began meeting in April–May 2021. Initially called the "G10" (five Democrats and five Republicans), it expanded over the summer to a working group of about 20. Key Republican members included Rob Portman (R-OH), Mitt Romney (R-UT), Bill Cassidy (R-LA), Susan Collins (R-ME), Lisa Murkowski (R-AK), and Mike Crapo (R-ID). Key Democrats included Sinema, Manchin, Mark Warner (D-VA), Jon Tester (D-MT), and Jeanne Shaheen (D-NH).

The negotiation focused tightly on a defined set of items: traditional, "hard" infrastructure (roads, bridges, transit, rail, water, broadband, energy grid). It explicitly excluded the more politically charged items in the original Biden proposal — the home-care expansion, the climate-policy elements, the major social-program expansions. Republicans had been unwilling to support those; Democrats agreed to pursue them through a separate reconciliation bill. The negotiation also focused on how to pay for the package. The compromise pay-fors included unused COVID relief funds, delayed Medicare drug rebate rules, customs user fees, and other less politically charged offsets, rather than the corporate tax increases that were nonstarters with Republicans.

By June 2021, the working group had produced a framework. The White House endorsed it. President Biden held a Rose Garden announcement with members of the bipartisan group on June 24, 2021, signaling executive support. Through July, the legislative text was drafted; the bill was introduced in the Senate at the end of July. After amendment debate and negotiation, the Senate passed the bill on August 10, 2021.

In the House, the IIJA hit a complication. Speaker Nancy Pelosi (D-CA), responding to pressure from the Congressional Progressive Caucus, initially linked the IIJA's House passage to the simultaneous passage of the much larger and more partisan Build Back Better Act — a roughly $3.5 trillion (later reduced) reconciliation bill containing the social-spending and climate elements that had been removed from the IIJA.

Progressives were skeptical that the IIJA's bipartisan negotiating partners (and Senators Manchin and Sinema) would actually deliver Build Back Better once the IIJA was law. Their negotiating leverage was the IIJA itself: if House progressives voted against it, the bill would die. Moderates argued that the House had no business holding up a Senate-passed bipartisan bill that the country needed, and that the Build Back Better fight was a separate question.

The standoff lasted from August into November 2021. Progressive Caucus chair Pramila Jayapal (D-WA) held the line. Moderates, including the Problem Solvers Caucus members, pushed for an immediate House vote. Pelosi attempted multiple compromise paths.

The bill finally passed on November 5, 2021, after Pelosi de-linked it from Build Back Better with assurances that the larger bill would be voted on later. (Build Back Better in its full form did not pass; a much-reduced version eventually became the Inflation Reduction Act of August 2022.) Six progressive Democrats voted against the IIJA, citing the broken linkage. Thirteen Republicans voted for it, providing the margin of victory.

Why it worked

A bipartisan accomplishment in 2021 is unusual enough to warrant analysis. Several factors made the IIJA possible:

1. Substantive coverage that could plausibly serve both parties' constituencies. Roads, bridges, and broadband are the kinds of infrastructure that matter in red states and blue states alike. A senator from Wyoming and a senator from Massachusetts both have constituents who would benefit from federal infrastructure spending in their states. The substance of the bill was less ideologically charged than most major legislation.

2. Clear scope. The G10 group held the line on excluding politically toxic items. The decision early on to exclude the social-spending and climate elements (deferring them to a separate reconciliation track) gave Republicans a cleanish "infrastructure-only" bill they could defend. It also allowed Democrats to pursue their broader agenda through a different track — even though, as it turned out, that broader track delivered less than progressives hoped for.

3. Real institutional relationships across the aisle. Senators Portman, Romney, Collins, Murkowski, Manchin, and Sinema had years of working relationships across party lines. Some of them had served together in committee. The G10 was not assembled cold; it was a continuation of relationships that had been built up over time. The fact that several of these senators have now retired (Portman in 2023; Romney in 2025; Sinema as an Independent in 2025; Manchin as an Independent in 2024) is one of the institutional concerns of recent years: the cross-aisle relationship infrastructure is itself wearing down.

4. Executive backing. President Biden personally endorsed the bipartisan framework rather than holding out for a partisan reconciliation-only approach. This was a real choice; many in his own party urged him to take the partisan track. Without his explicit endorsement, the bipartisan negotiation would not have survived its skeptics.

5. A pay-for compromise that neither side hated. The pay-fors — recycled COVID funds, delayed Medicare rebate rules, customs fees — were not popular with anyone, but they were not actively hated by anyone either. A clean tax increase or a clean deficit hit would have been a deal-breaker for one side or the other.

6. House moderate-progressive negotiation that ultimately resolved. The House standoff could have killed the bill. It did not, because Pelosi managed it well and because the Problem Solvers Caucus (operating within the larger Democratic conference) provided a procedural path that preserved both progressive and moderate priorities — at the cost of decoupling Build Back Better.

What it shows about Congress

The IIJA is one of the rare counter-examples to the gridlock thesis. Congress can still legislate at scale on a bipartisan basis. The conditions for it are demanding: substance that can plausibly serve constituencies across the spectrum; clear scope discipline; existing cross-aisle relationships; executive backing; a pay-for compromise; and managed intra-party dynamics on both sides. When all six conditions are met, bipartisan legislation passes. When any of the six is missing, it usually does not.

The lessons:

  • Bipartisanship is possible but rare, and it requires deliberate infrastructure. The G10 working group, the Problem Solvers Caucus, the relationships between Manchin/Sinema and a dozen Republican senators — these are not accidents. They are the result of members investing time in cross-aisle relationships when their own party rewards the opposite.

  • Scope discipline matters. A bipartisan bill that tries to do everything fails. A bipartisan bill that does one thing well, with the rest deferred to a separate track, can succeed.

  • The IIJA model — bipartisan core plus partisan reconciliation — has been replicated. The 2022 CHIPS and Science Act passed with similar Republican Senate support (17 Republicans). The Inflation Reduction Act passed without Republican Senate support but used the reconciliation track that the IIJA negotiations had implicitly accepted as the partisan-policy lane.

  • The conditions for bipartisanship are themselves eroding. The retirement of Manchin, Sinema, Portman, Romney, and others removes nodes in the cross-aisle relationship network. The replacement senators are, on average, more partisan in both directions. Whether the IIJA model can be replicated in 2025–28 is genuinely uncertain.

A note on what was not in the IIJA

It is also worth attending to what the bipartisan deal had to leave out. The original Biden administration proposal in March 2021 included substantial spending on home-care for elderly and disabled Americans, on early childhood education, on green-energy tax credits and direct climate spending, on housing construction and assistance, and on workforce development. Republicans were unwilling to support these elements. The IIJA negotiating group accepted the exclusion. Some of these elements were later picked up — in modified form — by the Inflation Reduction Act of 2022, which passed without any Republican votes through the budget-reconciliation process. Other elements, including the home-care and childcare provisions, did not pass at all in either bill.

This is the trade-off of the bipartisan track. A bill that can clear the Senate filibuster necessarily leaves out provisions that a meaningful share of the minority party opposes. From a progressive perspective, the IIJA was an underwhelming subset of a larger needed agenda. From a conservative perspective, the IIJA was already a substantial spending package and the larger original proposal was an unaffordable expansion of federal scope. Both positions are coherent. The bipartisan track, in this period, picked the policies that fit between those two poles — and even then, did not pass without a months-long internal Democratic fight.

The IIJA does not refute the chapter's account of congressional dysfunction. It complicates it. Congress still works, sometimes, when the conditions are right. The conditions are not always right, and they are getting harder to assemble. Both observations are true.