The thought of conservative immigration enforcement under Jeff Sessions as Attorney General is making some in the liberal D.C. establishment uneasy, according to a new report in Politico.

The publication wrote on Tuesday that Sessions’ commitment to solid immigration reform and border security has long placed him at odds with peers who have been less committed to taking action. Now, his appointment could mean a ready-or-not crackdown against illegal aliens.

“Sen. Sessions’ public statements and history on immigration give [us] real reason to be concerned that his positions, if confirmed as attorney general, would not uphold the values embodied in the Constitution to protect due process and fairness,” Greg Chen, director of advocacy for the American Immigration Lawyers Association, told Politico.

As Attorney General, Sessions will have great power over immigration courts, where non-citizens make their case before a judge as to why they should not be deported. Other actions that have been upheld under President Obama, like Deferred Action for Childhood Arrivals (DACA) could also face scrutiny under Sessions’ tenure in the Trump Administration.

The power of the post has precedent in such cases. Politico notes that former Attorney General Janet Reno issued a rule that granted legal protection to immigrants facing severe domestic abuse or fearing for their safety due to sexual orientation.

Karen Tumlin, legal director at the National Immigration Law Center, told Politico that an attorney general “can literally write opinions that have the force of law and interpret federal immigration law.”

The publication points to Sessions’ clear record fighting against so-called “sanctuary cities.” As the chair of the Judiciary Committee’s Subcommittee on Immigration and the National Interest, the Alabama Senator has sponsored legislation to end funding for sanctuary cities. Targeting municipalities that fail to comply with federal law could be one of his first official priorities.