There were a lot of illegal immigration to the U.S. during the Biden administration.

1. Rising encounters: raw numbers and how reporters count them

U.S. government data and independent trackers show that encounters at the southern border rose to levels well above those seen in the Trump years, with analyses noting roughly 5 million encounters in Biden-era timeframes versus about 1.4 million in comparable Trump-era windows, and DHS spreadsheets reporting millions processed, released, or removed during Biden’s term . Journalists and fact‑checkers warn that "encounters" mix apprehensions between ports of entry with inadmissible attempts at official ports and Title 42 expulsions, so the headline tallies can overstate what people mean by "illegal entrants who remain in the United States" .

2. Removals, expulsions and repatriations also climbed — complicating the narrative

Combined deportations, expulsions and other returns under Biden amount to millions of repatriations — Migration Policy cites nearly 4.4 million repatriations in the administration’s run, which makes enforcement activity substantial even amid record arrivals . FactCheck similarly finds that while raw encounter counts rose, removal rates under Biden were in some measures comparable or higher than under Trump (about 51% removed under Biden versus 47% under Trump in one framing), underscoring that higher arrivals produced both more releases and more returns .

3. Political sources and advocacy groups frame the numbers very differently

Republican House committees and conservative think tanks describe the increased flows as a failure of Biden policy and cite multi‑million figures of "inadmissible encounters" and releases to argue the administration encouraged illegal migration ^[1]. Conversely, analysts at Cato and Migration Policy emphasize structural drivers — labor markets, regional instability, and policies inherited from prior administrations — arguing that migration had already trended up before Biden and that enforcement actions increased under his watch as well . Both perspectives use overlapping data but with divergent interpretations and agendas ^[1].

4. Population estimates and the question of how many people actually stayed

Estimating how many unauthorized immigrants actually entered and remained is harder than counting encounters; some researchers report substantial net increases during the period, with estimates varying widely across methodologies — Cato’s residual‑based estimates suggested a multimillion increase while other demographers and DHS cite lower ranges and emphasize that many arrivals were returned or removed . Nonpartisan reporting notes that encounters peaking under Biden did not directly translate into a single simple increase in the undocumented population because expulsions, parole programs, asylum backlogs and removals all affected the net outcome .

5. What the evidence supports and where uncertainty remains

The factual record supports the claim that illegal‑border encounters and related immigration system activity rose to unprecedented levels during Biden’s presidency, producing millions of interactions, releases, and returns . However, experts disagree on attribution — how much is policy versus economics and regional crises — and on the proper metric for "how many illegal immigrants entered" versus were processed and returned; authoritative voices advise caution in translating encounters into a single population number without clarifying methods . Reporting differs in emphasis and motive: partisan fact sheets highlight total encounters as a policy failure ^[1], while policy centers and fact‑checkers focus on definitions, removals, and longer‑term population estimates .