Eric H. Holder Jr. was U.S. attorney general from 2009 to 2015.

Our nation's sense of morality — and of itself — is once again being tested.

President Trump has scrapped the Deferred Action for Childhood Arrivals (DACA) program, threatening to deport nearly 800,000 young, undocumented immigrants — the "dreamers" — and crassly justifying the decision by hiding behind a false interpretation of immigration law and our constitutional separation of powers.

DACA, which gave undocumented young people brought to the United States as children a chance to work and study here without fear of deportation, has been a dramatic success. The program provided a two-year grant of protection and a permit to work legally in the United States, after which enrollees were required to go through a renewal process. To qualify, immigrant youths had to meet a set of stringent criteria: When applying, they were required to have been enrolled in high school, have a high school diploma or equivalent, or have been an honorably discharged military veteran. In addition, they had to have lived in the United States continuously at least since June 15, 2007, and not have a criminal record suggesting they posed a threat to national security or public safety.

In other words, DACA was far from, as Attorney General Jeff Sessions suggested Tuesday, an "open-borders policy" that admitted "everyone." To the contrary, it was a beacon of hope for a narrowly defined group who crossed our borders before they could have fully understood what a "border" was.

Of course, as Sessions emphasized, we are a nation of laws, and the immigration system is no different. We must ensure that our laws are enforced to maintain the vitality, prosperity and security of our polity. But in painting DACA as a flagrant disregard for our constitutional separation of powers, Sessions exhibited a fundamental misunderstanding of what DACA did. The program was based on the well-established executive-branch authority to exercise prosecutorial discretion in setting enforcement priorities. Rather than grant legal status, DACA simply deferred enforcement action against immigrants who met certain qualifications and permitted them to work lawfully in the meantime. And despite Sessions's suggestion that President Barack Obama departed from established precedent in creating DACA, the practice of granting deferred action has been formally recognized as within the executive branch's authority since the Reagan administration.

But the Trump administration's revocation of DACA more than rests on legal misconceptions; it also is based on a misleading characterization of the dreamers. Sessions has justified the end of the program by suggesting that dreamers took jobs away from Americans and that "failure to enforce" immigration laws puts our nation "at risk of crime, violence and even terrorism." This portrait stands in stark contrast with the dreamers whom I, and many others, know, admire and love.

The dreamers I know are husbands and wives, children and parents, cousins and friends. They are business owners, neighbors and soldiers who fight for our nation. Their work in sectors from technology to law to finance continually betters our nation. They are not and should not be defined by their immigration status. They must be defined by their character and contributions to this country, their devotion to our communities, and the dreams they espouse. Their America is our America. As Obama has said, they are Americans "in their hearts, in their minds, in every single way but one: on paper."

We must look to the truth etched in our past and avoid a tendency to focus on short-term political impulses when it comes to immigration. Immigrants created the United States. Tenacity, entrepreneurship and fearlessness have defined immigrants throughout the centuries and serve as a common bond between my immigrant father and Trump's immigrant mother.

After immigrating to America from Barbados, my father served in the Army in World War II only to be refused service — while in uniform — at a lunch counter in the very nation he defended. Nevertheless, his persistence and unshaken belief in this country and the unique American opportunities made available to him enabled his son to become attorney general of the United States. That's the possibility that comes with immigrating to this country, the dream that this country fosters and has made real. Remembering these truths can help us avoid the self-inflicted wound that will be caused by turning away from the principles that indeed made America great — again and again and again.

I'm calling on all Americans to see and treat dreamers as our own, because they are our own. Congress must urgently enact legislation to restore their ability to build lives in this country. States must resist Trump's inevitable deportation efforts. The private sector must come together to defend its employees. Americans must raise their voices — and use their ballots. If we are to remain true to our heritage and who we claim to be, we must stand with the dreamers.