Trump expands military use at the southern border. Are there legal limits?

President Trump's expansion of federal military use at the southern border has sparked a legal debate over whether it exceeds the Posse Comitatus Act, established in 1878 to limit federal troops from engaging in civilian law enforcement. The act prohibits federal forces from acting as law enforcers on U.S. soil without explicit authority. Yet, Trump's administration is using military zones at the border to temporarily detain and search individuals, potentially bypassing this restriction. This move has drawn criticism for blurring the lines between military and law enforcement roles, risking legal ambiguity and undermining military readiness.