A crowd of more than 200 protesters gathered to oppose County Circuit Judge Hannah Dugan's arrest and felony charges.

Specifically, the complaint says Dugan assisted Eduardo Flores-Ruiz, a Mexican immigrant, avoid being arrested by federal immigration officials at the Milwaukee County Courthouse after he appeared in her courtroom for a pre-trial conference on April 18.

The arrest marks a significant escalation in the Trump administration's crackdown on immigration, as well as in its battles with judges across the country.