How did monthly US-Mexico border encounters under Biden compare to Trump and Obama administrations?
Executive summary
Monthly U.S.–Mexico border “encounters” were far higher on average during the Biden presidency than during the Trump presidencies, with CBP recording roughly 11 million encounters over Biden’s four years and single-month peaks above 130,000 in 2023–24; by contrast, early months of Trump’s second term and many months of his first term saw much lower monthly totals after aggressive enforcement actions and pandemic-era closures [1] [2] [3]. Sources agree numbers surged under Biden (millions of encounters) and fell sharply after policy changes in 2024–25, but they differ on how to attribute causes and on measuring “unique people” versus repeated encounters [3] [4] [5].
1. Biden’s term: sustained high encounters, then a sharp 2024 decline
CBP recorded very large totals during the Biden years, with reporting that about 11 million border encounters were logged over his four years in office and media analyses noting 3.2 million encounters in 2023 alone and roughly 6.4 million encounters at places between ports of entry in a prior Monitor analysis—figures that made Biden-era monthly averages markedly higher than during Trump’s first term [1] [6] [3]. Those high totals reflect both increased migration flows and CBP’s encounter metric, which counts each time a person is taken into custody (so repeat attempts can inflate totals)—the U.S. government does not publish net entries or unique-person counts, a limitation analysts repeatedly note [3]. After spring–summer 2024 policy shifts — notably a Biden proclamation limiting asylum processing and other enforcement measures — officials and outlets reported steep drops in encounters, for example a cited 60% fall between ports of entry and months with encounters falling from peaks such as 137,000 in March 2024 toward far lower December 2024 figures [7] [4].
2. Trump (first term) and patterns under hard-line measures
During Trump’s first term, encounters fell sharply after 2017 policy changes and again during the COVID-era restrictions that drove fiscal 2020 totals down; however, Trump also faced a 2019 surge that rose well above earlier months [8]. Contemporary comparisons emphasize that Trump-era monthly drops were real and sometimes dramatic, but that surges occurred too — the pattern under Trump was ebb and flow tied to policy moves, court rulings and seasonal effects [4] [8]. Reporting from early 2025 about Trump’s return to the presidency shows very low monthly encounter counts in his first months back in office, with government statements framing those as historic lows compared with Biden-era monthly averages [9].
3. Trump (second term) early months: rapid decline and administration claims
Government and advocacy reporting from early 2025 show a rapid decline in encounters after Trump’s second inauguration: DHS and supporters pointed to months with monthly totals far below Biden’s monthly average (DHS framed nine months under Trump as having fewer total enforcement encounters than one typical Biden month) and media described “record-low” apprehensions tied to immediate policy reversals [9] [10]. Independent outlets and NGOs documented similar declines and attributed much of the drop to canceling CBP One and restrictive asylum measures — but they also raised human-rights and humanitarian concerns about access to protection [10] [11].
4. What the metric “encounters” does — and does not — tell us
All sources stress that “encounters” measure the number of times CBP meets migrants, not unique individuals nor net immigration. That means high encounter totals under Biden partly reflect repeat crossings, shifts in migrant origins and family composition, expanded use of the CBP One app at ports of entry, and changing enforcement priorities [3] [5]. Because agencies do not publish net entries or unique-person tallies in a way that resolves multiple encounters, direct comparisons of administrations must be read with that limitation in mind [3].
5. Competing explanations and political framing
Reports show bipartisan political claims about cause and credit. Administration officials have credited their own policy actions for both increases and declines: Biden officials cited their 2024 proclamation and Mexico’s enforcement for the post-2024 fall [7] [2], while Trump’s team cast immediate post-inauguration drops as proof of an effective crackdown and touted deportation numbers [9] [12]. Independent analysts and outlets caution that timing, seasonal cycles, Mexican cooperation, and app-based processing also move the numbers — meaning both parties can over-attribute cause without long-term data [4] [2].
6. Bottom line and reporting limits
Available sources consistently show Biden’s years had far larger cumulative and average monthly encounter counts than Trump’s first term, with major peaks in 2023 and early 2024 and a pronounced decline after asylum and processing changes in mid-2024; Trump’s early months in his second term and some months in his first yielded much lower encounter totals [6] [4] [9]. But because “encounters” are not unique-person counts and because policy, seasonal and international factors affect flows, available reporting cannot conclusively isolate how much of the difference is caused solely by either president’s actions rather than other variables [3] [4].