The U.S. Department of Justice has expanded its nationwide legal challenge to state policies providing in-state college tuition to illegal aliens, filing lawsuits against Arizona, New Mexico, Oregon and Washington. The latest cases bring the number of states facing DOJ lawsuits over the policies to 21.

The Justice Department argues that the state programs conflict with federal law by allowing illegal aliens to receive in-state tuition rates or financial assistance that may not be available to U.S. citizens from outside those states. The lawsuits seek to block enforcement of the policies.

The latest filings target programs that provide in-state tuition based on state residency or other requirements rather than immigration status. The complaints also challenge state financial aid and scholarship programs available to illegal aliens.

Associate Attorney General Stanley E. Woodward Jr. said the four states were “pushing citizens to the side” by providing benefits to illegal aliens and argued that the policies violate federal restrictions enacted by Congress.

The lawsuits are part of a broader Justice Department campaign launched under the Trump administration. Previous cases have targeted tuition policies in states including Texas, Oklahoma, Kentucky, Minnesota, Nebraska, Illinois, Virginia, New Jersey, Kansas, Massachusetts, Rhode Island, Maryland, Colorado, New York, Connecticut and Vermont.

The department has already reached agreements or secured favorable outcomes in several of the cases. Texas and Oklahoma, for example, moved to end policies providing in-state tuition to certain illegal aliens after DOJ challenges. Other states have continued defending their programs in court.

The federal government’s legal argument centers on the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, which restricts states from providing certain postsecondary education benefits to illegal aliens on the basis of residency unless the same benefits are available to U.S. citizens regardless of their state of residence.

The latest lawsuits signal that the Justice Department intends to continue challenging state tuition policies rather than treating the issue as limited to a handful of states. Additional litigation could follow as the department reviews similar policies across the country.