when presented with a bill that traded the legalization of Dreamers for more border security but did not reduce legal immigration, only eight Republican Senators voted yes. However, 37 voted for a bill that legalized the “Dreamers,” added more border security, and substantially reduced legal immigration.

In their book White Backlash, the political scientists Marisa Abrajano and Zoltan Hajnal cite a poll showing that 61 percent of Americans believe that most Latino immigrants are undocumented even though only about a quarter are. “When Americans talk about undocumented immigrants, Latinos or immigrants in general,” they note, “the images in their heads are likely to be the same.”

Trump replaced the legal-illegal distinction with one that turned out to have more resonance on the activist right: The distinction between white Christian immigrants and non-white, and non-Christian ones.

Trump has turned that distinction on its head. He’s willing to legalize the “Dreamers”—who came to the United States illegally—so long as the number of legal immigrants goes down. He has not only blurred the GOP’s long-held moral distinction between legal and illegal immigration. In some ways, he’s actually flipped it—taking a harder line on people who enter the U.S. with documentation than those who don’t.

He would support a path to citizenship for undocumented immigrants only if Congress brought the number of legal immigrants down.

A temporary work visa (TWV) should be created that would allow Mexican nationals to remain in the U.S. to work for a limited period. The visa could authorize work for a definite period--perhaps three years--and would be renewable for an additional limited period; permit unlimited multiple entries for as long as the visa was valid; allow complete mobility between employers and sectors of the American economy; and entitle the holder to "national treatment."

Before Sept. 11, the U.S. government had stationed more than four times as many border enforcement agents on the Mexican border as along the Canadian one, even though the latter is more than twice as long and has been the preferred border of entry for Middle Easterners trying to enter the U.S. illegally

None of the 19 hijackers entered the country illegally or as immigrants. They all arrived in the U.S. with valid temporary nonimmigrant tourist or student visas. None of them arrived via Mexico, and none were Mexican. Sealing the Mexican border with a three-tiered, 2,000-mile replica of the Berlin Wall patrolled by thousands of American troops would not have kept a single Sept. 11 terrorist out of the U.S.

in the early 1950s, the Immigration and Naturalization Service more than doubled the number of Bracero visas, enough to meet growing demand, especially in the agricultural sector. As a result, illegal immigration from Mexico plummeted to almost nothing during the second half of the decade. Illegal migration was supplanted by legal migration.

a 1995 Labor Department study found that undocumented workers who were legalized in the 1980s as part of the IRCA "amnesty" provisions responded by investing in their skills and education.

Low-skilled immigrants, a category that describes most migrants from Mexico, benefit the U.S. economy by filling jobs for which the large majority of American workers are overqualified and that they are unwilling to take.

During the long boom of the 1990s, and especially in the second half of the decade, the national unemployment rate fell below four percent and real wages rose both up and down the income scale during a time of high immigration levels. According to a study by the Council of Economic Advisers, household incomes rose strongly from 1993 through 1999 across all income groups, including the poorest one-fifth of American households. The poverty rate fell by three percent during the 1990s, and almost 10% among African-Americans. Those remarkable gains occurred during a decade of large immigration inflows, including low-skilled workers from Mexico.

Immigration aides the U.S. economy by providing workers to fill gaps in the labor market. Immigrants tend to fill occupations where the gap between the supply of workers and the demand for them is greatest, typically in the highest- and lowest-skilled jobs. That hourglass shape of the immigration labor pool complements the native workforce, where a much larger share of workers falls in the middle range in terms of skills and education. As a result, immigrants do not typically compete for the kinds of jobs held by the vast majority of American workers. Instead, they migrate to those segments of the job market where most Americans are over- or underqualified.

The migration of Mexican workers to the U.S. is a rational and mutually beneficial response to underlying economic needs on both sides of the border. Immigration--like the international flow of goods, services, and capital--typically benefits most people in both the sending and receiving countries.

The remote topography and hostile desert climate have resulted in the deaths of thousands of migrants since the crackdown began. In 2001, 336 migrants were found dead along the border from dehydration and other causes, down slightly from 377 deaths in 2000, but up sharply from the death toll in earlier years.

Immigration is ultimately driven by demand for labor in the U.S. market. Mexicans migrate to the U.S. not simply because wages are higher, but because Americans want to hire them.

During that period, Douglas Massey of the University of Pennsylvania estimates that 28,000,000 Mexicans entered the U.S. and 23,400,000 eventually returned to Mexico, for a net immigration total of 4,600,000. In other words, when free to enter and work in the U.S., more than 80% of Mexican migrants still chose eventually to return to their homeland.

Most Mexicans who migrate to the U.S. do not come intending to settle permanently. They come to solve temporary problems of family finance--by saving dollars and sending them back home in the form of remittances.

Long-time opponents of immigration have seized on 9/11 to argue against legalization of Mexican migration in favor of drastic cuts in existing levels of legal immigration. The connection between the Sept. 11 attacks and illegal immigration from Mexico is nonexistent, though.None of the 19 hijackers entered the country illegally or as immigrants. They all arrived in the U.S. with valid temporary nonimmigrant tourist or student visas. None of them arrived via Mexico, and none were Mexican. Sealing the Mexican border with a three-tiered, 2,000-mile replica of the Berlin Wall patrolled by thousands of American troops would not have kept a single Sept. 11 terrorist out of the U.S.

"For many, legalization appears to have been a turning point. Suddenly, there was a surge of investment in language skills, education, and training," the study found. Specifically, 43% of Mexican men undertook some skill-enhancement training following legalization, "more than a doubling of the previous rate of human-capital accumulation for most origin groups."

The migration of Mexican workers to the U.S. is a rational and mutually beneficial response to underlying economic needs on both sides of the border. Immigration--like the international flow of goods, services, and capital--typically benefits most people in both the sending and receiving countries.

With the number of low-skilled jobs expected to grow by more than 700,000 a year, and a shrinking pool of Americans willing to fill those jobs, Mexican migrants provide a ready and willing source of labor to fill the growing gap between demand and supply on the lower rungs of the labor ladder.

During the long boom of the 1990s, and especially in the second half of the decade, the national unemployment rate fell below four percent and real wages rose both up and down the income scale during a time of high immigration levels. According to a study by the Council of Economic Advisers, household incomes rose strongly from 1993 through 1999 across all income groups, including the poorest one-fifth of American households. The poverty rate fell by three percent during the 1990s, and almost 10% among African-Americans. Those remarkable gains occurred during a decade of large immigration inflows, including low-skilled workers from Mexico.

That hourglass shape of the immigration labor pool complements the native workforce, where a much larger share of workers falls in the middle range in terms of skills and education. As a result, immigrants do not typically compete for the kinds of jobs held by the vast majority of American workers. Instead, they migrate to those segments of the job market where most Americans are over- or underqualified.

Immigration is ultimately driven by demand for labor in the U.S. market.

What, then, should the United States do about illegal immigration? A fence won't work, mass deportation won't work, and every plan the government has adopted in recent decades has done nothing but enriched and empowered crime syndicates that have transformed a modest problem into an intractable one

A billion here, a billion there--these are all big numbers. But that is only one side of the equation. The workers also bring significant economic benefit to the country. Take Texas, a state with one of the largest populations of immigrants who crossed the border illegally. A 2006 report by the state comptroller estimated they added $17.7 billion to gross state product, including contributing $424 million more to state revenue than they consumed in government services, such as education, health care and law enforcement.

Some use individual taxpayer identification numbers on their official payment forms; others use fake Social Security numbers (the Internal Revenue Service recognizes those are bogus but happily accepts the money). They also pay significant sums into both the Social Security Trust Fund and Medicare, but because few of them qualify for benefits, they take little out. In fact, the Social Security Administration includes over $7 billion in annual contributions from these immigrants in its calculations of the trust fund's solvency.

Immigrants create jobs. It's simple economics--if more people spend money, more jobs are created. Workers without documentation still pay rent, buy food and clothes, go to the movies. Just through their daily existence as consumers, they are spurring economic activity.

the violent crime rate in America dropped 34 percent, and the property crime rate fell 26 percent. That same report found that Mexican immigrants--including those who entered the U.S. legally and illegally--had an incarceration rate in 2000 of 0.7 percent, one-eighth the rate of native-born Americans of Mexican descent and lower than that of American-born whites and blacks of similar socioeconomic status and education.

Farmers railed against the law, fearful that they would no longer have access to the many workers who harvested crops, and the Chamber of Commerce protested the financial sanctions on employers. So, over the years, the requirements compelling employers to thoroughly vet potential hires for their immigration status were rolled back.

these "illegals" commit far fewer crimes per capita than lesser educated, native-born Americans. They do take jobs, but they also create more jobs for Americans. They use some social services, but a lot of that is offset by how much they pump into the economy. The aggressive enforcement of U.S. immigration laws has given rise to an organized crime network that smuggles people across the border, often while subjecting them to rape, kidnapping and even murder. And as for the most popular, easy-sounding solutions, such as building walls and having mass deportations? They are ridiculous and would require spending hundreds of billions of dollars to accomplish virtually nothing, while upending the American economy.

have concluded that undocumented immigrants have had a positive (seventy-four percent) or neutral (eleven percent) impact on the U.S. economy.

Even though illegal aliens make little use of welfare, from which they are generally barred, the costs of illegal immigration in terms of government expenditures for education, criminal justice, and emergency medical care are significant.

However the estimated wage suppression and fiscal costs are relatively small, and economists generally view the overall economic benefits of this workforce as significantly outweighing the costs."

"Illegal immigration costs U.S. taxpayers about $113 billion a year at the federal, state and local level… The annual outlay that illegal aliens cost U.S. taxpayers is an average amount per native-headed household of $1,117... Education for the children of illegal aliens constitutes the single largest cost to taxpayers, at an annual price tag of nearly $52 billion...

"In 2010, the average unlawful immigrant household received around $24,721 in government benefits and services while paying some $10,334 in taxes. This generated an average annual fiscal deficit (benefits received minus taxes paid) of around $14,387 per household. This cost had to be borne by U.S. taxpayers... Under current law, all unlawful immigrant households together have an aggregate annual deficit of around $54.5 billion."

In 2012, researchers at the Cato Institute estimated that a mass deportations policy would reduce economic growth by around $250 billion per year. Those costs would not be evenly distributed: Those at the very bottom of the income distribution, particularly those without a high school diploma, may even earn higher wages in the absence of undocumented immigrants.

"Undocumented immigrants contribute significantly to state and local taxes, collectively paying an estimated $11.64 billion a year. Contributions range from almost $2.2 million in Montana with an estimated undocumented population of 4,000 to more than $3.1 billion in California, home to more than 3 million undocumented immigrants.