It seems just about every American has an opinion about mass deportations. It’s too bad most of those views are so uninformed.

I’ve been writing about immigration for 35 years, and I still haven’t figured it out.

My take is complicated by the branches on my family tree.

I don’t have a single undocumented immigrant in my lineage. Three of my grandparents were born in Texas, and the fourth came from Mexico to the United States as a boy with his family around 1915 during the Mexican Revolution. The whole family came legally.

With the exception of the Chinese who were barred from entering this country by the Chinese Exclusion Act of 1882 — a piece of legislation so racist that you’d think it was intended to keep out Mexicans — no one could come illegally until after the Immigration Act of 1924.

The example of my Mexican grandfather proved to me that immigrants are the best thing about America.

But there’s another branch on that tree. My father is a retired law enforcement officer who spent 37 years on the job. Whether it happens on the U.S.-Mexico border or the steps of the U.S. Capitol, I don’t take lawlessness lightly. Never have.

So I’m the perfect guide through a national conversation about the possibility of mass deportations that is likely to be filled with pitfalls. Watch out for dishonesty, fear, racism, partisanship, wishful thinking and short memories on the part of liberals and conservatives alike.

President-elect Donald Trump says that his second at-bat will be guided by a simple philosophy: “Promises made, promises kept.”

What a lot of Americans want to know is whether one of those kept promises will be Trump’s oft-repeated pledge to “launch the largest deportation program in American history.”

Hearing that, you have should have at least five questions.

No. 1: Will Trump keep his word? He doesn’t always. When he ran for president the first time, in 2016, he also promised “mass deportations.” It never happened.

No. 2: If, this time, it does happen, who will be the target? Criminal immigrants who after entering the country unlawfully, or overstaying a legal visa, went on to commit serious crimes — an approach favored by Tom Homan, the former police officer, and U.S. immigration official who Trump recently named “border czar”? Or will the net be wider and include any undocumented immigrant in the United States, even law-abiding, hardworking and taxpaying model citizens — an approach favored by Stephen Miller, the former Trump adviser who the president-elect recently appointed deputy White House chief of staff?

No. 3: How exactly will all this work? The far-right hardliners who call into radio shows want police officers, U.S. immigration officials and even the U.S. military to go city by city, neighborhood by neighborhood and door to door to ferret out anyone who fits the profile of an undocumented immigrant (read: brown skin).

No. 4: What’s the cost of this modern-day Operation Wetback, the mass deportation effort that began in 1954 and removed more than a million people? The American Immigration Council, a nonpartisan advocacy group, estimates that all of Trump’s immigration policies would cost taxpayers more than $300 billion. Nativists claim there are as many as 20 million undocumented people in this country, and U.S. Immigration and Customs Enforcement estimates that it costs about $10,000 to deport one person. Do the math. That’s about $200 billion. That’s a lot of money to waste given that — as any of us who live within 100 miles of the U.S.-Mexico border can tell you — most of the people who get removed have a curious habit of coming back. That’s human nature. And it’s nearly impossible for law enforcement to control.

No. 5: Finally, just how much damage would a mass deportation initiative do to our society, with neighbor turned against neighbor and U.S. citizens caught up in the net and harassed, and maybe even deported? Hey, it’s happened before. It could happen again. Besides, Homan recently told CBS’ “60 Minutes” that he thinks whole families should be deported including individuals who were born in the United States. If you want to know just how horribly un-American that would be, talk to Japanese Americans in their 80s about what it was like to spend part of their childhood behind barbed wire in massive internment camps.

My God, as Americans, we’re supposed to learn from our worst mistakes. Not rush headlong into repeating them.

Ruben Navarrette’s email is ruben@rubennavarrette.com