Attorney General Jeff Sessions exercised his authority Monday as the ultimate reviewer of the immigration court system to overrule a series of Obama-era decisions that were allowing the radical expansion of the American asylum system.

Asylum is part of the Immigration and Nationality Act (INA). In 1980, it was defined to allow entry to the United States for people who face persecution, typically by their home countries’ governments, for their “race, religion, nationality, membership in a particular social group, or political opinion.”

Traditionally, the “social group” category was seen as akin to the others, a defined group with identifiable characteristics whose members faced danger and persecution. Asylum was for anti-Communist Afghans who for refused to be drafted into the Soviet occupation’s army, Jehovah’s Witnesses who faced arrest for holding meetings, and so on.

During the Obama administration, certain decisions in the immigration courts and by the Board of Immigration Appeals (BIA) which oversees them began to push the boundaries of the “social group” category. In 2014, after years of court rejecting similar claims, the BIA approved “married women in Guatemala who are unable to leave their relationship” as a social group qualifying for asylum. The case Sessions overruled today expanded that protection to “El Salvadoran women who are unable to leave their domestic relationships where they have children in common.”

Sessions writes in his 31-page opinion:

I reiterate that an applicant for asylum on account of her membership in a purported particular social group must demonstrate: (1) membership in a particular group, which is composed of members who share a common immutable characteristic, is defined with particularity, and is socially distinct within the society in question; (2) that her membership in that group is a central reason for her persecution; and (3) that the alleged harm is inflicted by the government of her home country or by persons that the government is unwilling or unable to control[.]

Coverage of Sessions’s action has focused largely on the specifics of domestic violence victims and women with children, but the ruling has much further reaching implications. In its own terms, it seeks to halt the rapid expansion of the asylum concept to cover victims or even potential victims of regular private criminal activity.

Open borders groups and the immigration bar have for years sought to turn the exception of asylum for persecuted groups into a rule that people more likely to be victims of ordinary crime in their home countries have a right to move to the United States. In 2005, for example, an immigration lawyer unsuccessfully asked a federal appeals court to expand asylum to cover “young, attractive Albanian women,” because they were more likely to be forced into prostitution. In 2011, a lawsuit asked a different court to do the same for people who were “resistant” to gangs.

Sessions’s opinion Monday, Matter of A-B, likely forecloses, for now, this effort to use existing immigration law to force the United States to admit more and more people who enter the country without authorization and claim asylum based on dangers inherent in the less developed countries from which they come.

Monday morning, Sessions announced the decision would be coming at the Executive Office for Immigration Review’s (EOIR) Annual Training Conference for Immigration Judges in Tysons Corner, Virginia.

“The asylum system is being abused to the detriment of the rule of law, sound public policy, and public safety —  and to the detriment of people with just claims,” Sessions said in his prepared remarks for the immigration judges, continuing:

Saying a few simple words — claiming a fear of return—is now transforming a straightforward arrest for illegal entry and immediate return into a prolonged legal process, where an alien may be released from custody into the United States and possibly never show up for an immigration hearing. This is a large part of what has been accurately called, “catch and release.”

“Beginning in 2009, more and more aliens who passed an initial USCIS credible fear review were released from custody into the United States pending a full hearing,” Sessions said of the system that led to this year’s “caravan” debacle.

Sessions explained:

Powerful incentives were created for aliens to come here illegally and claim a fear of return. In effect, word spread that by asserting this fear, they could remain in the United States one way or the other. Far too often, that rumor proved to be true. The results are just what one would expect. The number of illegal entrants has surged. Credible fear claims have skyrocketed, and the percentage of asylum claims found meritorious by our judges declined.

This backdrop set the stage for the so-called “caravan” of Central American migrants who reached Southern California this April. Making credible fear claims to USCIS officials at the San Ysidro, many of these otherwise illegal migrants were able to join Americas 700,000-strong line of pending immigration cases, and stuff in the U.S. while they await a ruling.

Long before the caravan, Sessions was trying to draw attention to the issue of asylum abuse, asking Congress to “close loopholes and clarify our asylum laws” in October.

Monday’s action represents another example of Sessions using his own authority as attorney general to affect these same aims. Last month, he used the same authority to restrict the circumstances in which immigration judges can drop deportation cases. Sessions has also shifted prosecutors and immigration judges to the border to more quickly handle asylum claimants and sought, where possible, to prosecute immigration lawyers engaging in asylum fraud to keep their clients in the U.S.

“We have not acted hastily, but carefully,” Sessions told the immigration judges of his Monday asylum ruling. “In my judgment, this is a correct interpretation of the law. It advances the original intent and purpose of the INA, and it will be your duty to carry out this ruling.”