How many illegal immigrants entered the US under the first Trump administration
Executive summary
There is no single, authoritative count of how many people “entered illegally” during Donald Trump’s first term (Jan 2017–Jan 2021); immigration scholars and agencies rely on imperfect proxies — border apprehensions, “gotaways,” expulsions and population estimates — that point to large flows in some years but roughly stable or slightly falling undocumented population totals by the end of his term (depending on the source) [1] [2] [3] [4].
1. What the question really asks — entry vs. population vs. encounters
Asking how many “illegal immigrants entered” conflates three different measures: raw border “encounters” or apprehensions recorded by CBP, counted expulsions/removals, and net changes in the estimated unauthorized population; each measures different things and none yields a precise count of unique people who successfully entered illegally during 2017–2020 [2] [5] [3].
2. What the enforcement numbers show — big spikes, not a tidy total
Border enforcement logs show volatile annual totals rather than a single cumulative “entries” number: fiscal-year apprehensions peaked at 851,508 in FY2019 under Trump according to Pew’s compilation of CBP data, and monthly apprehensions were high in the final months of his term (e.g., ~71,000–75,000 in Dec 2020–Jan 2021) [2] [1]. Those apprehensions measure encounters with agents — not unique successful entries — and do not capture “gotaways” (migrants observed but not stopped) or repeat attempts by the same individuals [2] [6].
3. Population estimates give a different picture — stable or slightly down
Household- and survey-based estimates suggest the unauthorized population did not explode during Trump’s first term and may even have declined: one analysis using the Current Population Survey estimated the illegal-immigrant population fell to about 10.22 million by January 2021, a drop of roughly 1.26 million from 2019 levels [3]. Other organizations and think tanks argue the undocumented population was broadly similar across the Trump years, noting that enforcement increased detentions and deportations while legal immigration was constrained [4] [7].
4. Removals and expulsions — enforcement removed hundreds of thousands
Deportations and expedited removals were substantial during Trump’s first term: ICE removals and CBP expulsions together produced yearly totals in the hundreds of thousands (for example, one analysis cites a high single-year deportation total of 347,250 in FY2019 and notes Title 42-era expulsions change the arithmetic when included) [5] [8]. These removals reduce the undocumented population but do not translate cleanly into how many people “entered” because many removals involve people present before 2017, or repeated crossers who are removed and later try again [5].
5. Why precise cumulative entry counts don’t exist — methodological limits
Government and academic sources explicitly warn that annual apprehensions, “gotaways,” removals and survey-based population estimates each have limitations: apprehensions can double-count repeat crossers, “gotaways” are undercounted or reported with a lag, Title 42 expulsions changed enforcement practice, and household surveys have sampling error — so no reliable tally exists of unique unauthorized entries during 2017–2020 [6] [9] [3].
6. Bottom line — what can be said with confidence
It is accurate to say that under Trump’s first term border encounters were high in some years (notably FY2019’s 851,508 apprehensions) and that enforcement produced large numbers of removals and detentions, yet survey-based estimates show the unauthorized population was roughly stable or modestly lower by January 2021 (around ~10.2 million in one CPS-based estimate), meaning there is no defensible single-number answer for “how many illegal immigrants entered” during the first Trump administration [2] [5] [3] [4].