On September 17, 2025, the Knight Institute filed an amicus brief in Khalil v. Trump, a case challenging the Trump administration’s unlawful detention and attempted deportation of Mahmoud Khalil for his pro-Palestinian speech. The district court granted Mr. Khalil’s motion for a preliminary injunction, finding that Secretary of State Marco Rubio’s determination that Mr. Khalil was deportable under the foreign policy ground was likely unconstitutionally vague, and ordered Mr. Khalil’s release on bail. The government appealed the decision to the Third Circuit.

The amicus brief urges the Third Circuit to affirm the district court’s decision, and makes two points in support of that outcome. First, the Fifth Amendment’s vagueness doctrine protects individuals from arbitrary and standardless deprivations of their liberty interests, and these safeguards are especially important when First Amendment rights are at stake. Second, as demonstrated by recent testimony in AAUP v. Rubio, the government targeted Mr. Khalil as part of a broader ideological deportation policy whose features compound the concerns that were the bases of the district court’s decision.

Status: Briefing on appeal ongoing.

Case Information: Khalil v. Trump, No. 25-2162 & 25-2357 (3d Cir.)