The Trump administration is taking its campaign against illegal immigration to the workplace.

The raids by federal agents on dozens of 7-Eleven convenience stores last week were the administration’s first big show of force meant to convey the consequences of employing undocumented people.

“We are taking work-site enforcement very hard,” said Thomas D. Homan, the director of Immigration and Customs Enforcement, in a speech in October. “Not only are we going to prosecute the employers who knowingly hire the illegal aliens, we are going to detain and remove the illegal alien workers.”

When agents raid workplaces, they often demand to see employees’ immigration documents and make arrests. But after the agents leave, it is difficult for the government to meaningfully penalize businesses that hire unauthorized immigrants.

Instead, according to law enforcement officials and experts with differing views of the immigration debate, a primary goal of such raids is to dissuade those working illegally from showing up for their jobs — and to warn prospective migrants that even if they make it across the border, they may end up being captured at work.