Congress is on the verge of passing the largest economic rescue package in U.S. history. The $2.2 trillion bill would send one-time checks to millions of Americans, provide billions in emergency funding to hospitals on the coronavirus’s front lines, significantly expand unemployment benefits and offer half a trillion dollars in emergency loans to small businesses, industries, and state and local governments.

Once signed into law, this will be the third rescue package enacted this month to address the national emergency. The first provided $8 billion of emergency funding for the health-care system. A second offered paid sick and child-care leave and free coronavirus testing to a tune of $100 billion. And even with this third package, many lawmakers suggest more aid will be needed soon.

Here are four takeaways from Congress’s action this week.

Responding to crisis and avoiding blame

Congress has always moved quickly to respond to national emergencies, including the Great Depression, the 9/11 terrorist attacks, and the global financial crisis. That’s true, no matter which party controls the White House, Senate or House.

Perhaps lawmakers simply rise to the occasion. As Senate Minority Leader Charles E. Schumer (D-N.Y.) put it on the floor Wednesday night, “Government is the only force large enough to staunch the bleeding.” Or as Senate Majority Leader Mitch McConnell (R-Ky.) stressed earlier this week, “The American people expect us to act.”

But it’s just as likely that congressional leaders push members into action by warning that failing to act means losing at the polls. Lawmakers hold their noses and cooperate, not wanting the blame for failing to act. With covid-19 infections spreading exponentially, deaths rising daily and millions of people out of work, Congress knew it had to act fast. That pressure gives leaders more power, as rank-and-file lawmakers have little time to probe a massive bill’s details.

So it’s no wonder that when several conservative GOP senators made a rear guard move to alter the bill, they failed. Sens. Tim Scott (S.C.), Lindsey O. Graham (S.C.), Ben Sasse (Neb.), and Rick Scott (Fla.) claimed that the bill was too generous to unemployed workers. McConnell didn’t want his party blamed for blowing up the deal. So he told the dissidents they could offer a floor amendment under rules that all but guaranteed it would fail.

A bipartisan agreement in partisan times

House Speaker Nancy Pelosi (D-Calif.) and Treasury Secretary Steven Mnuchin personally negotiated the second emergency aid package, which subsidized new leave benefits during the crisis. For that bill, McConnell gave “ball control” to Mnuchin, letting him negotiate on behalf of both the White House and Republican lawmakers. When several Senate Republicans subsequently threatened to derail the Pelosi-Mnuchin deal, McConnell told his colleagues to “gag and vote for it.”

To gain the upper hand on the economic relief bill, McConnell made the first move. He pulled together bipartisan groups of senators and asked them for proposals in their committees’ areas of expertise. When Republicans balked at some of the Democrats’ demands, McConnell called up a bill that included only Republicans’ priorities, daring Democrats to vote against it. They did. Twice.

Maybe McConnell thought he could divide the Democrats, making it easier for Republicans, in further negotiations, to get more of what they wanted in the bill. Or maybe McConnell wanted to blame Democrats for blocking action in a crisis. Either way, McConnell’s gambit failed: Democrats stuck together, and some of their demands even attracted GOP support — including oversight and transparency rules for new corporate lending programs.

The parties resumed negotiations. Two days later, senators voted for a deal that delivered both parties’ top priorities and a historic level of government relief.

Learning, maybe, from the Wall Street bailouts

The original GOP proposal centered on a $500 billion fund that would offer loans to corporations and small businesses slammed by the pandemic. Some of the funds would have helped particular industries, like the airlines; over $400 billion would have gone to the Federal Reserve for emergency lending to businesses.

Mnuchin pleaded with senators not to call the fund a bailout, eager to avoid any comparisons to the highly unpopular 2008 Wall Street bailouts during the global financial crisis. Democrats were happy to oblige: Instead, they panned the GOP proposal as a mammoth corporate slush fund.

In fact, the $500 million bailout fund resembled the Treasury’s initial 2008 proposal in one particularly startling way: Just as then-Treasury Secretary Henry M. Paulson had proposed in 2008, the original proposal would have given Mnuchin nearly unfettered control of the fund, with little requirements for disclosure or opportunities for review. As in 2008, Democrats pushed back, forcing Republicans to agree to oversight mechanisms nearly identical to the ones in the 2008 law.

Rocky roads ahead

Senate leaders congratulated themselves Wednesday night for stepping up to the plate in the face of the looming economic and health disasters. But Thursday’s news of record unemployment claims — over 3 million, a number sure to rise in the coming weeks — suggested that even a $2.2. trillion relief package could quickly become obsolete.

So far, the Democrats and the Republicans have very different priorities for what they’d like to see in the next relief bill. What’s more, although leaders could call back members earlier, the Senate is in recess until April 20, and House members will likely also be scattered in their home districts, or in some cases in self-quarantine — and neither chamber’s rules now allow for remote voting. That means making a deal and getting lawmakers back to town to vote could be equally steep challenges.