The futures of roughly 580,000 DACA recipients and their families are at stake as Republican attempts to end the program make their way through the court system.
At fewer than 54,000 apprehensions, the number is also the lowest since August 2020 during the Trump administration, and it is similar to September totals in 2018, 2019 and 2020.
In the middle of a rant about immigration, Trump said, "We got a lot of bad genes in our country." His campaign said later that "bad genes" was only in reference to murderers.
The new rules, which toughen restrictions announced in June, bar migrants from being granted asylum when U.S. officials deem that the southern border is overwhelmed.
Two law enforcement officials said many of those migrants crossed into the U.S. under previous administrations, and that the total includes people serving U.S. prison sentences.
By visiting the southern border, Harris seeks to tackle a political vulnerability, with polling frequently showing she trails Trump on immigration and border issues.
Some Democrats concede that they need to prioritize border security and enforcement before they can get to other goals, like expanding legal pathways for newcomers.