Within hours of a presidential proclamation, the ACLU filed a lawsuit to block new asylum rules.
The new regulation requires asylum seekers crossing the U.S.-Mexico border to cross at a port of entry. The lawsuit claims that rules violates the Immigration and Nationality Act.
That law says, "Any alien who is physically present in the United States or who arrives in the United States (whether or not at a designated port of arrival) ... may apply for asylum."
The White House cited an executive order from President George W. Bush to defend its action. That order was upheld by the Supreme Court, but dealt with immigrants before they reached U.S. soil.
The Trump administration's new rule applies to people who do make it to U.S. soil. It says, "aliens who enter the United States unlawfully through the southern border ... will be ineligible to be granted asylum."
The ACLU wants the court to declare the presidential proclamation invalid and prevent the administration from trying to enforce it.