What was different about the illegal immigration from 2020 to 2024 compared to previous years?
Executive summary
From 2020 through 2024 illegal immigration shifted from pandemic-constrained lows into a multifaceted surge driven by policy changes, new parole programs and changing migration composition, followed by a policy-and-enforcement reaction that pushed numbers down late in 2024; encounters and population estimates rose markedly compared with the pre-2020 period [1][2][3]. Political actors pushed competing narratives — Congress’ Homeland Security Committee framed the increases as a security and criminality crisis [4], while data-driven research groups emphasized demographic and procedural drivers such as releases, paroles and the end of pandemic-era Title 42 expulsions [5][2].
1. Surge of encounters and a different scale
Border and CBP encounter counts exploded after FY2020: analysts cite millions of inadmissible encounters from FY2021–FY2024 and committee briefings describe a jump measured in the millions compared with 2017–2020 levels [4][1], a scale that translated into Census and Pew adjustments to population estimates and contributed to record-high foreign-born counts in 2024 in some analyses [6][3].
2. Composition changed — more families, children, and new origin countries
The mix of migrants shifted: family-unit encounters tripled between FY2020 and FY2024 (from roughly 11.6% to about 35.1% of encounters), and encounters involving children surged, changing operational burdens at the border and in federal custody systems [1]. At the same time the geographic origins broadened beyond traditional source countries to include larger flows from Caribbean and South American nations tied to specific parole policies [1][7].
3. Policy levers created new legal pathways and reporting artifacts
The rise was not solely clandestine crossings; government parole programs and OFO paroles — including a CHNV parole program that admitted hundreds of thousands before being paused — created lawful-admission pathways that nonetheless contributed to higher net arrivals and to changed official accounting [4][3][5]. Those administrative mechanisms complicate comparisons with prior years because some arrivals counted in 2022–2024 were admitted under parole rather than evading inspection [3].
4. Title 42 and pandemic-era effects masked and then amplified trends
Title 42 expulsions and travel restrictions suppressed irregular migration starting in March 2020, creating a low baseline; when Title 42 was lifted and pandemic restrictions relaxed, flows rebounded quickly, producing a steeper-looking rise compared with the 2017–2019 baseline [2][8]. That means part of the “difference” between 2020–2024 and earlier years is a return from an atypical pandemic trough into a new operational equilibrium shaped by post-2020 policy changes [2].
5. Enforcement, geopolitics and a late-2024 slowdown
By mid-to-late 2024 federal and Mexican enforcement shifts, plus new U.S. restrictions on asylum processing and intensified removals, drove encounters down markedly in the second half of 2024, with CBP reporting sharp month-to-month declines in some sectors and DHS reporting large numbers of removals and flights [9][10]. Analysts caution that these declines reflect a mix of policy deterrence, bilateral action and operational constraints, not a permanent return to pre-2020 patterns [10][8].
6. Conflicting framings and political incentives
The data produced starkly different political narratives: House committee materials highlighted criminality and security risks tied to the surge (including claims about parole fraud and watchlist apprehensions) [4], while research centers and DHS-oriented publications emphasized methodological causes — counting changes, parole programs and pandemic distortions — and warned against short-term readings [3][5][2]. Each source carries implicit agendas: oversight committees seek policy leverage while research groups prioritize trend interpretation and DHS frames enforcement success.
7. What remains uncertain and why comparisons are hard
Estimating net unauthorized populations and “gotaways” remains fraught because administrative practices, parole classifications and data collection changed during 2020–2024; official dashboards and independent researchers both note that some 2022–2024 counts incorporate CBP releases and parole figures that would not have existed in earlier comparisons [3][11]. Where sources do not provide clear attribution, reporting must refrain from definitive causal claims and instead document the measurable shifts in encounters, composition and policy that made 2020–2024 visibly different from prior years [1][2].