Trump is gone and Biden is gathering steam. But now's not the time to stop worrying.

For those of us accustomed to doomscrolling through dire news stories and bulletins during nightly bouts of insomnia, this should be a time of hope, or at least less dread. Donald Trump is out of office and if President Joe Biden did nothing else in his next four years, his legacy would be assured by the new $1.9 trillion COVID-19 relief law — a poverty-fighting rebuke to “trickle-down economics” that sends money directly where it's needed instead of to rich “job creators” with demanding shareholders.

As if that alone weren't enough to warm the most nerve-wracked liberal heart, the Senate has confirmed more than 20 of Biden's Cabinet-level appointees, including 10 women and 11 men and women of color. Beyond COVID-19, Biden himself is making fast moves on everything from infrastructure investment to the U.S. Postal Service to federal judges and a top Supreme Court prospect. And he might have set a land-speed record for executive orders to reverse actions by his predecessor.

Still, this is no time to stop worrying.

Majority could vanish in an instant

For a while, there was a whole genre of "sluggish start" narratives that detailed all the reasons Biden was trailing other presidents — Trump's insistence that he won an election he lost, which hampered the transition, built to a deadly attack on the U.S. Capitol and led to a second Trump impeachment trial in the Senate, plus two Jan. 5 special elections in Georgia that left Senate control undecided until results were certified Jan. 19 — over two weeks after the rest of the new Congress had been sworn in.

Now the lagging indicators are catching up. Almost all of Biden's Cabinet is finally in place (still behind Barack Obama and Bill Clinton but now ahead of Trump and George W. Bush), he has signed his first major bill, and he has scheduled his first full-fledged formal news conference for Thursday — weeks behind most presidents, but seriously, who's going to remember that or any of the rest?

It's clear that Biden and his advisers have taken many lessons from the Obama years and are already applying them. But you can only control what you can control. When you have a 50-50 Senate with Vice President Kamala Harris as the tiebreaker, your control is beyond precarious. Moments like this are rare. If you don't seize them, they can slip away before you even realize it.

Case in point: The glory days of a filibuster-proof 60-vote Senate Democratic majority in 2009. As former Obama White House aide Dan Pfeiffer points out, that wasn't true for most of the year. "Senator Arlen Specter had not yet switched parties, and Al Franken’s election was tied up in the courts," so Democrats started with only 58 votes, some of them quite conservative, Pfeiffer wrote last week.

Specter became a Democrat at the end of April 2009. Franken was sworn in on July 7. Democrats finally had their 60 votes to break a Republican filibuster and pass bills by a simple majority. They intended to use their power to pass the historic, badly needed Affordable Care Act. But they didn't act fast enough.

Perhaps they lacked situational awareness, or the resolve to accept a grim reality: Sen. Edward Kennedy, a champion of the ACA and of health care throughout his career, had been diagnosed with a malignant brain tumor in May 2008, at age 76. Average survival time for glioblastoma patients is 12-18 months. He died in August 2009.

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At that point, the ACA was mired in bipartisan Senate negotiations. Yet after months of talks, and a bill shaped more to their liking, not one Senate Republican voted for the ACA on Christmas Eve 2009. It passed with 60 Democratic votes during a four-month period when appointed Democrat Paul Kirk held Kennedy's seat.

What usually comes next are negotiations between the House and Senate, agreement on a final version and votes in both chambers. What Democrats did not expect, did not even see as a glimmer in the distance, was that a Republican — Scott Brown — would win Kennedy's Senate seat in January 2010. The Democrats' 60-vote supermajority vanished yet again.

They saved the ACA with a fancy parliamentary strategy centered on the House passing the Senate version. Democrats went on to lose the House later in 2010 and the Senate in 2014.

No negotiations to nowhere

The moral of this story is that you never have as much time as you think you do.

Less than a week after Democrats officially took over the Senate this year, Vermont Democrat Patrick Leahy — who'll turn 81 this month — was hospitalized. It was a short stay, but it's a reminder of how quickly 50-50 can turn to 50-49, with no role for a tiebreaking Democratic vice president. Especially when 18 Senate Democrats are 70 or older (and one of them, California's Dianne Feinstein, is 87).

From Biden on down, Democrats are conveying a suitable sense of urgency. The House is churning out bills on major priorities at a brisk pace. Senate Majority Leader Chuck Schumer, meanwhile, told Stephen Colbert on Thursday night that "failure is not an option" for Democrats and dismissed Senate Republican leader Mitch McConnell's threat of a scorched-earth Senate: "It's not going to stop us."

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But the Senate is not built for speed. On top of that, some Democrats, including Biden and Schumer, say they want to give Republicans a chance to behave constructively before going scorched earth themselves in the service of policies Americans strongly support — such as stricter gun laws, spending on infrastructure and elections that are secure, fair and convenient.

Forging ahead on COVID-19 relief without Republicans was a heartening sign. It's a template Democrats should hold close. They have a window to accomplish all they can as fast as they can. No wasting time, no tempting fate, no invitation to history to repeat itself with futile ACA-like negotiations to nowhere. This moment is all any of us have.

Jill Lawrence is the commentary editor of USA TODAY and author of "The Art of the Political Deal: How Congress Beat the Odds and Broke Through Gridlock." Follow her on Twitter: @JillDLawrence

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This article originally appeared on USA TODAY: Biden and Democrats should act fast on guns, voting and infrastructure