While over the past year many categories of immigration litigation were little changed, marked growth occurred for naturalization and habeas corpus lawsuits. Habeas lawsuits increased by over 85 times during the past year, while naturalization suits were 1.8 times higher than in March 2025.

While most naturalization suits sought court orders to compel the government to act on an immigrant's naturalization application, to hold hearings on the application or challenged the decision itself, the sharp jump in habeas corpus lawsuits has been driven by the rapid increase in the Trump administration's actions to arrest, detain and rapidly deport thousands of immigrants.

A habeas corpus lawsuit requests that a judge order a detainee brought before the court and government officials explain why they have the authority to detain that person. The legal right to file a habeas corpus suit is enshrined in Article 1, Section 9 of the U.S. Constitution. This right is centuries old and serves as an essential bulwark against arbitrary imprisonment. Over the last year, immigrant rights attorneys have mounted major campaigns to file such suits and counteract the Immigration and Customs Enforcement's (ICE) expedited and increasing detention and deportation activity.

A total of 82 out of 90 federal judicial districts in the United States saw habeas corpus lawsuits filed during the last six months (October 2025 - March 2026). A total of 10 of these districts had more than 1,000 suits filed. The Western District of Texas (San Antonio) topped this list with 3,448 suits instituted. Two districts had over 2,000 suits filed during this period: the Eastern District of California (Sacramento) with 2,797 filings and the Southern District of Texas (Houston) with 2,305 lawsuits filed.

An additional seven districts had more than 1,000 suits. Two of these were located along the southwest border with Mexico: the Southern District of California (San Diego) with 1,740 habeas lawsuits and Arizona with 1,104 suits filed during the last six months. The fifth and sixth place in the top ten were the Central District of California (Los Angeles) with 1,370 habeas filings, and Minnesota with 1,200 suits. Widespread news coverage had been given to unprecedented ICE-targeted immigration enforcement actions in each of these districts. Other ICE enforcement activity in the Middle District of Florida (Tampa) resulted in 1,196 habeas suits, in the Western District of Michigan (Grand Rapids) resulting in 1,084 suits and in New Jersey with 1,010 filings. These three districts comprised the rest of the ten districts with the greatest number of habeas lawsuits filed during the last six months.

Relative to population size, five additional districts made the top ten. These included the Western District of Louisiana (Shreveport), New Mexico, the Middle District of Georgia (Macon), the Southern District of Georgia (Savannah), and the Western District of New York (Buffalo).

The full report provides additional details. TRAC has also added the latest case-by-case data on immigration civil litigation to its online tools on its website at https://tracreports.org.