After fitful starts, Mr. Biden has presided over the easing of the Covid pandemic and accompanying restrictions despite vaccine resistance among many, especially on the political right. But he has failed to quell a surge of migration at the southwestern border, where attempted crossings have hit record highs, and Republicans blame him for a wave of crime, which actually began while Mr. Trump was still in office.

Mr. Biden has worked to reverse Mr. Trump’s impact on the judiciary, pushing through more judicial appointments through the Senate in his first two years than his predecessor had, but the pipeline has slowed in recent months with the absence of an ailing Senator Dianne Feinstein, Democrat of California, from the Judiciary Committee. Mr. Biden fulfilled his promise to appoint the first Black woman to the Supreme Court, Ketanji Brown Jackson.

Where he has not been able to work his will on lawmakers, he has relied on an expansive interpretation of his executive power to achieve policy goals, most notably his decision to forgive $400 billion in student loans. But such actions are inherently subject to court challenges, and analysts expect the Supreme Court to overrule the student loan decision.

In the international arena, Mr. Biden worked to revitalize international ties that had frayed under Mr. Trump, recommitting to NATO and rejoining the Paris climate change accord. But his effort to resurrect the Iran nuclear agreement abandoned by Mr. Trump has gone nowhere.

Mr. Biden’s withdrawal of American forces from Afghanistan after 20 years turned into a debacle, leading to a swift and brutal takeover of the country by the Taliban and a chaotic withdrawal of troops and allies, with fleeing Afghans swarming American planes and a suicide bomber killing 13 American troops and 170 civilians.

Although Mr. Trump has criticized Mr. Biden over the episode, the president was carrying out a pullout deal that his predecessor struck with the Taliban, a pact that one of Mr. Trump’s own national security advisers called a “surrender agreement.” Some experts argue the fiasco at the Kabul airport emboldened President Vladimir V. Putin of Russia to assume that Mr. Biden was weak.

But Mr. Biden rallied the world when Mr. Putin invaded Ukraine last year to isolate Moscow and cut off much of its financial ties with the West. With bipartisan support, Mr. Biden has committed more than $100 billion to arm Ukraine’s military and enable its government and people to survive the Russian onslaught. American assistance helped the Ukrainians surprise Russian invaders by preventing the takeover of their capital and most of the country, but the situation remains volatile.