immigration

As the Trump administration considers steps to implement what the president has called extreme vetting of foreigners at the border, one aspect of security screening has already been amped up.

The number of people who have been asked to hand over their cellphones and passwords by Customs and Border Protection agents has increased nearly threefold in recent years. This is happening to American citizens as well as foreign visitors.

The Justice Department is following through on an executive order to withhold as much as $4.1 billion in federal grants from so-called "sanctuary cities," generally defined as places where local law enforcement limit their cooperation with federal authorities on immigration enforcement.

When you think of illegal immigration in the U.S., do you picture a border crosser or a visa overstayer? A family or a single person? A farmworker or a waiter?

People living in the U.S. without legal status are frequently invoked in American politics — especially in recent months. But the conversation is often short on facts about the millions of people who fall into this category.

Back in 2011, Alabama passed what was then considered the nation's strictest immigration law. Much of it was later struck down by the courts.

Now, the law offers a snapshot of potential challenges ahead for the Trump administration.

For Fernanda Herrera, a senior at Samford University outside Birmingham, Ala., the current climate surrounding immigration has her scared, just as the Alabama law did in 2011.

"I don't know if I'm going to see my parents tomorrow," Herrera says.

Her father crossed the Mexican border illegally when she was two.

An estimated 11 million immigrants live and work in the United States illegally. Their fate is one of the big policy questions facing the country. The story of how that population grew so large is a long one that's mostly about Mexico, and full of unintended consequences.

Prior to the 1920s, the U.S. had few restrictions on immigration, save for a few notable exclusions.

"Basically, people could show up," says Jeffrey Passel, of the Pew Research Center.

For workers in Mexico, crossing into the U.S. made a lot of economic sense, then and now.

Updated at 2:30 p.m. ET

President Trump has signed a new executive order that temporarily blocks visas from being issued to citizens of six majority-Muslim countries, revoking and replacing a controversial, now-suspended executive order known as the travel ban.