One of our readers, Susan from Connecticut, writes:

“Could you do an in-depth report on illegal immigrants in the US? Most do not walk across the border. Most fly in, with legal visas, and then overstay the terms of their visit. And most of those illegals are not from Mexico or Central America. A wall would not affect that.”

Great question. Here are some impressive numbers from the Department of Homeland Security:

In 2017, 702,000 people who entered the U.S. legally overstayed their visas, thereby becoming illegal. The number of people who illegally cross the border, mostly the southern border, was 361,993. So for all the talk of a wall, the vast majority of those who are in the United States illegally did not cross the U.S.-Mexico border. By the way, the 361,993 is down from 1.6 million in 2000.

In 2017, 52 million foreign nationals legally entered the U.S. A little over one percent overstayed. The leading country for overstays? Canada. From USA Today:

Canadians made up the largest group of visa overstays, with more than 92,000 remaining in the United States in 2017 despite being expected to leave.

Mexicans made up the second-largest group of visa overstays, with more than 47,000. The report does not include people who cross via land borders, so those numbers would likely increase for both Canadians and Mexicans.

Of the 38 Visa Waiver Program countries, Portuguese citizens had the highest overstay rate (1.81 percent), followed by Hungarians (1.55 percent) and the Greek (1.25 percent).

Of the Visa Waiver Program countries, British citizens had the highest number of visa overstays (25,694) followed by the French (16,456) and Spaniards (13,780).

The overall number of visa overstays has continued dropping in fiscal year 2018 as more people left the country voluntarily or through deportations. By January 2018, the number fell to 494,710, and by May, it fell to 421,325.

Add to this the number of illegal immigrants has dropped to its lowest level in a decade. From Pew:

“The decline is due almost entirely to a sharp decrease in the number of Mexicans entering the country without authorization.

“But the Mexican border remains a pathway for entry by growing numbers of unauthorized immigrants from El Salvador, Guatemala and Honduras. Because of them, Central America was the only birth region accounting for more U.S. unauthorized immigrants in 2016 than in 2007.

“There were 10.7 million unauthorized immigrants living in the U.S. in 2016, down from a peak of 12.2 million in 2007, according to the new estimates.”

“…Increasingly unauthorized immigrants are likely to be long-term U.S. residents: Two-thirds of adult unauthorized immigrants have lived in the country for more than 10 years.”

Not all unauthorized immigrants enter the U.S. illegally. Our new analysis finds a rising share arrive legally, but overstay their visas https://t.co/qgal2vqf1K — PewResearch Hispanic (@PewHispanic) December 28, 2018

No doubt Republicans and Democrats could get behind meaningful immigration reform. But all the focus on a wall is just politics for personal gain.