GPT added a caveat to the Trump list; on the Biden list it adds none.

There is no fully objective ranking, and several outcomes reflected global shocks, Congress, courts, or inherited conditions. Still, the most commonly cited major failures are:

• 1.The chaotic Afghanistan withdrawal
• •Although Biden inherited the withdrawal agreement, the August 2021 evacuation was poorly planned and executed.
• •Kabul fell faster than anticipated, desperate scenes unfolded at the airport, many Afghan partners were left behind, and an ISIS-K bombing killed 13 U.S. service members and scores of Afghans.
• •The episode damaged perceptions of U.S. competence and credibility.

• 2.Inflation and the cost-of-living crisis
• •Inflation reached 9.1% in June 2022, while food, rent, energy, and other essentials rose sharply.
• •Pandemic disruptions and Russia’s invasion of Ukraine were major causes, but the administration initially underestimated inflation and described it as “transitory.”
• •Many economists believe the $1.9 trillion American Rescue Plan added demand to an already recovering economy, worsening inflation at the margin.

• 3.Failure to manage the southern border and asylum system
• •Border encounters reached record levels, asylum cases accumulated, and cities struggled to house new arrivals.
• •The administration reversed some Trump-era measures without having an effective replacement system ready and waited until late in the term to impose tougher restrictions.
• •Congress’s refusal to pass immigration reform—and Republicans’ rejection of a 2024 bipartisan border bill—shared responsibility, but the administration’s response was still widely viewed as reactive.

• 4.Handling of the Israel–Gaza war
• •Biden strongly supported Israel after the October 7 attacks but struggled to use U.S. leverage to limit civilian suffering, ensure adequate humanitarian aid, or obtain an earlier durable ceasefire and hostage agreement.
• •Shifting language about “red lines” and continued arms support produced criticism that U.S. policy was inconsistent or insufficiently conditioned.
• •The issue damaged U.S. standing abroad and divided Biden’s domestic coalition.

• 5.An overly cautious and incremental Ukraine strategy
• •The administration successfully rallied NATO and helped prevent Ukraine’s defeat, but critics argue that delays in providing certain weapons and restrictions on their use gave Russia time to adapt.
• •Biden also failed to deter the original invasion or produce a clear, achievable end-state for U.S. policy.
• •Responsibility for the war rests with Russia, so this is more accurately a criticism of strategy than blame for the conflict itself.

• 6.Insufficient progress on housing affordability
• •Home prices, rents, mortgage rates, and homelessness remained severe problems.
• •Many underlying causes were decades old and largely controlled by state and local zoning policies, while interest rates were set by the Federal Reserve.
• •Nevertheless, federal initiatives were too limited or slow to produce visible relief during Biden’s term.

• 7.Failure to enact several central Democratic priorities
• •Voting-rights legislation, comprehensive immigration reform, a federal abortion-rights law, major police reform, and the original Build Back Better package did not pass.
• •The Supreme Court also struck down Biden’s broad student-loan cancellation plan.
• •Narrow congressional margins and unified Republican opposition were important constraints, although critics fault Biden for overpromising and misjudging what could be enacted.

• 8.Poor communication and delayed acknowledgment of Biden’s age
• •The administration often failed to communicate economic and legislative accomplishments in ways that resonated with voters.
• •Biden and his advisers resisted concerns about his age and capacity until his poor June 2024 debate performance made them unavoidable.
• •His late withdrawal from the presidential race left Democrats little time to conduct a normal nomination process and is widely regarded as a major political and leadership failure.

The three failures with the broadest public and historical significance are likely Afghanistan, inflation, and border management, with Gaza policy and the handling of Biden’s age and reelection campaign close behind.

Assuming you mean the first Trump administration (2017–2021), the most significant failures—judged by human impact, institutional damage, stated goals, and lasting consequences—include:

• 1.COVID-19 response
• •The administration was slow to expand testing, repeatedly minimized the threat, promoted inconsistent public-health messaging, and politicized masks and reopening.
• •More than 400,000 Americans had died by the time Trump left office. Operation Warp Speed was a major success, but vaccine development did not offset broader failures in preparedness and coordination.

• 2.Attempt to overturn the 2020 election
• •Trump refused to accept a verified electoral defeat, pressured state and federal officials, encouraged efforts involving alternate electors, and promoted unsupported fraud claims.
• •These actions culminated in the January 6 Capitol attack and severely damaged confidence in democratic institutions and the peaceful transfer of power.

• 3.Family separation and broader immigration-policy failures
• •The “zero tolerance” policy separated thousands of children from their parents, with inadequate systems for tracking and reunification.
• •The administration also failed to achieve its central promises: Mexico did not pay for the border wall, much of the construction replaced existing barriers, and Congress never enacted comprehensive immigration reform.

• 4.Failure to replace the Affordable Care Act
• •Despite repeated promises to repeal and replace Obamacare with a superior plan, the administration never produced or enacted a comprehensive replacement.
• •Its efforts created uncertainty for insurers and patients and threatened protections for people with preexisting conditions.

• 5.Large deficits despite a strong pre-pandemic economy
• •The 2017 tax law reduced corporate taxes but did not generate the promised sustained surge in growth or pay for itself.
• •The federal deficit rose from roughly $585 billion in fiscal year 2016 to about $984 billion in 2019, before pandemic spending caused it to increase dramatically further.

• 6.Trade war with China
• •Tariffs raised costs for American importers and consumers, triggered retaliation against U.S. farmers, and required tens of billions of dollars in agricultural aid.
• •The “Phase One” agreement did not produce the promised structural changes or Chinese purchases, while the bilateral trade imbalance remained large.

• 7.Iran policy
• •Trump withdrew from the Iran nuclear agreement without securing a stronger replacement.
• •Iran subsequently expanded its nuclear activities, while regional tensions increased. The “maximum pressure” campaign inflicted economic pain but did not achieve a new deal or durable limits on Iran’s nuclear program.

• 8.North Korea diplomacy without denuclearization
• •Trump’s summits with Kim Jong Un reduced tensions temporarily but produced no enforceable denuclearization agreement.
• •North Korea continued developing its nuclear weapons and missile capabilities while gaining international legitimacy from presidential-level meetings.

• 9.Afghanistan agreement and strategic incoherence
• •The 2020 deal with the Taliban set a U.S. withdrawal timetable, marginalized the Afghan government, and included weak enforcement mechanisms.
• •Although the final withdrawal occurred under Biden, Trump’s agreement substantially constrained the options available and strengthened the Taliban’s position.

• 10.Climate and environmental policy
• •The administration withdrew from the Paris climate agreement, weakened numerous environmental regulations, and promoted fossil-fuel development while climate risks intensified.
• •Some rollbacks were blocked by courts or later reversed, creating regulatory instability without a durable national climate strategy.

• 11.Administrative dysfunction and ethics problems
• •The administration experienced extraordinary senior-level turnover, frequent acting appointments, inconsistent policymaking, and repeated conflicts-of-interest concerns.
• •Numerous policies were struck down because agencies failed to follow required legal and administrative procedures.

• 12.Damage to alliances and U.S. credibility
• •Trump frequently disparaged NATO allies, questioned traditional security commitments, and treated alliances transactionally.
• •Although he pushed allies to spend more on defense and brokered the Abraham Accords, his unpredictability weakened trust in U.S. commitments and complicated coordination with partners.

The two failures with the broadest consequences were likely the mishandling of COVID-19 and the effort to overturn the 2020 election—the first because of its human toll, and the second because it threatened constitutional government.