One year ago Thursday, then-President Trump was in with a fighting chance of reelection, Sen. Bernie Sanders (I-Vt.) still clung to some hope of becoming the Democratic presidential nominee, and the nation’s unemployment rate was under 4 percent.

Two days later, a national emergency was declared as COVID-19 spread.

Now Trump is a Florida retiree, President Biden will address the nation on Thursday evening and Americans are still grappling with an economic crisis that saw unemployment peak at almost 15 percent. 

The full impact of the pandemic will be debated for years to come. But the crisis has already remade American politics.

It was, for a start, the primary reason Biden won the 2020 election.

Even though Biden won the popular vote handily, his Electoral College victory was much tighter.

If Arizona, Georgia and Wisconsin — each of which Biden carried by less than 1 percentage point — had gone the other way, the number of electoral votes would have been evenly split between the two candidates.

It’s tough to make the case that, absent COVID-19, Trump couldn’t have held onto enough votes to eke out wins in those states.

Republican pollster David Winston said that, in a non-coronavirus scenario, “certainly the economic situation and the low unemployment rate … would push it in [Trump’s] direction.”

The pandemic also arguably helped Biden seal his victory in the Democratic primary. He had moved into the front-runner spot before the de facto national lockdown was declared, winning the crucial South Carolina primary on Feb. 29 and dominating Super Tuesday on March 3.

But Sanders's supporters still held out hope that he could mount a comeback, perhaps scoring big in debates and making Democratic voters take a more critical look at Biden. 

The pandemic put paid to all that. 

The candidates at first curtailed, then completely abandoned, traditional rallies. The first debate after the national emergency was declared, scheduled for March 15 in a Phoenix theater, was moved to the antiseptic surroundings of a CNN studio in Washington.

There were to be no more opportunities for Sanders to disrupt Biden’s glide path to the nomination. 

“Our campaign relied heavily on grassroots organization and large rallies to get the word out and to mobilize people, and that became much more difficult,” said Jeff Weaver, a longtime Sanders aide who had served as his 2016 campaign manager. 

Weaver added that the chances of Sanders creating some kind of game-changing moment were sharply diminished after the pandemic hit. 

“Understandably, the pandemic came to occupy American consciousness on all levels, and to the exclusion of most other things. It pushed even politics out,” he said.

But the impact on Trump was even more profound.

In the RealClearPolitics (RCP) average of battleground states on March 11 last year, Trump lagged Biden by a small margin of 2.6 percentage points. Three months later, that deficit had more than doubled, to 5.4 points.

Trump was always going to have a tight reelection race because he is such a polarizing figure. But the pandemic — and his response to it, in which he underplayed its seriousness and infamously suggested people could inject themselves with bleach — made the climb much tougher.

Trump’s overall job approval rating was underwater by almost 9 points in the RCP average on March 11. By July 11, the deficit was almost 15 points.

The first COVID-19 vaccine was approved for emergency use in the United States in mid-December, by which time Trump was a lame duck — despite his false claims of having won the election.

Biden is set to reap political dividends from the nation’s recovery from COVID-19, assuming he continues the progress that has been made in his administration’s early days. He recently pledged that there would be enough vaccinations for every adult American by the end of May. 

The new president enjoys healthy approval ratings on his COVID-19 response. In an Economist/YouGov poll conducted Feb. 27-March 2, his actions on the pandemic won the approval of 52 percent of adults and the disapproval of 35 percent.

There are bigger questions that will take time to answer, including whether the depth of the crisis has made Americans more amenable to large-scale government intervention.

The signs are promising for progressives. The $1.9 trillion stimulus deal that passed the House on Wednesday — Biden is expected to sign it on Friday — is broadly popular.

The centerpiece of the legislation is the distribution of checks of up to $1,400 to eligible citizens. The government doling out money is never going to be unpopular. 

Democrats clearly hope that other measures in the bill that are more tenuously connected to the pandemic — an expansion of the child tax credit, and more money for infrastructure spending and after-school programs — will be similarly popular.

Some on the left hope a real shift in national priorities is at hand. Rep. Ro Khanna (D-Calif.), a leading progressive, has called the bill “an ideological revolution on behalf of justice.”

But centrist figures, including former Treasury Secretary Larry Summers, have warned that the huge stimulus risks stoking inflation.

Republicans, meanwhile, say Democrats could be overreaching.

“They are using this particular situation, and the desire to get COVID relief, and then putting other things into that bill that have minimal relationship to the situation at hand,” said Winston, the GOP pollster. “There were a lot of Republicans who wanted to vote for a pure COVID bill and that opportunity never arose.”

The year of COVID-19 will be etched on Americans’ minds for a lifetime.

The changes it has wrought on life and politics are seismic.

The Memo is a reported column by Niall Stanage.