Melania Trump and I would both have to leave the United States. We weren’t born here.

In fact, if everyone who is not born in the U.S. left tomorrow, 1 in 7 people living in the country would disappear. That would certainly make your commute easier. But a lot of other things would get much, much harder.

You see, immigrants tend to be of working age, and they are more likely to be in the labor force than people born in the United States. So if all immigrants went back to where they came from, the U.S. workforce would lose 28 million workers or fully 17.4% of the entire labor force.

Many jobs would not be done and many businesses would be scrambling. If you had an accident driving on one of those less congested freeways, chance are that there would not be enough doctors or nurses to take care of you. More than a quarter of all physicians and surgeons in the United States are immigrants.

The impact on California would be greater than The Big One. Former Governor Schwarzenegger would have to return to Austria. He would be joined by about 10.5 million other Californians who would leave for other countries; about 28% of the state’s population would disappear. That exodus would decimate the economy of the state, from the high tech sector to agriculture, from restaurants to construction.

The state, counties and cities would lose billions of dollars in income tax, sales tax and property taxes. If immigrant Californians left with their children, half of the state’s student population, from kindergarten to grade 12, would disappear before classes resume in September. This means that about half of all teachers would have to be laid off, schools would close, and those families still in California would have to drive or bus their kids to schools further from their homes.

At UC Berkeley, two-thirds of our students are first or second generation children of immigrants. In my department, at least 13 of 30 faculty members were born in another country. The university would lose over a dozen stellar teachers and world-renowned researchers in just one unit.

Now multiply that across campus, from computer engineering to law, from the business school to cellular and molecular biology. UC Berkeley’s reputation as a global research university – the best public university in the world, many claim – would quickly diminish without foreign-born students, staff and faculty.

An interesting thought experiment is to consider the immigrants who helped build the university and think what would have happened if they had never lived in the U.S. The list includes Peder Sather, whose wealth helped build Sather Gate and the Campanile, and former Chancellor Chang-Lin Tien, an acclaimed mechanical engineer. A list of essential immigrants would also have to include staff working as custodians, groundskeepers and accountants, the people who keep the university going.

But beyond the impact on the university, on the state or on the national economy, rejecting people out of hand because of where they were born is fundamentally un-American. Everyone in the country, born here or not, should denounce such rhetoric.