For the second time in less than two months, the Daily Bruin Opinion page has seen fit to print a personal attack on me. Once again, the submission, this time written by Justino Mora, an alumnus, is a diatribe full of factual errors and guilt-by-association arguments. The errors in the earlier piece were so blatant, The Bruin was forced to correct them in the online version.

The title of my response to the first submission about me was “Demonizing opposition does not solve issue of excessive immigration.” I noted that essentially all of California’s rapid population growth is due to immigrants and their U.S.-born offspring. According to the U.S. Census Bureau, California already contains the four most densely populated urban areas in the entire U.S., with Los Angeles standing at the very top. Indeed, seven of the top 10 such areas are located in California. California contains one of the world’s biodiversity hot spots, but this biodiversity is being overrun by more and more people flooding into our state.

The position of Californians For Population Stabilization on legal immigration levels is similar to those of two distinguished national commissions. The first was The Commission on Population Growth and the American Future, chaired by John D. Rockefeller III in 1972, which recommended immigration levels not exceed 400,000 per year. The second was the report from the U.S. Commission on Immigration Reform, chaired in 1995 by Barbara Jordan, a Democratic, African-American congresswoman, which proposed a core immigration admissions level of 550,000 per year. An immigration level of around 500,000 per year would still be the most generous of any country on earth.

Californians For Population Stabilization is concerned that the leadership of both major political parties want to increase legal immigration levels while not seemingly caring about illegal immigration. Such policies are driving the U.S. toward a projected population of 500 million and beyond, a disaster for the U.S. environment and that of the entire world, given the large per capita environmental impact of a typical American.

It is appropriate to recall Winston Churchill’s comment from his 1959 “Memoirs of the Second World War” about British politics before World War II.

“The left and the right joined forces with fatuity at a terrible price to be paid later,” Churchill said.

Rather than addressing these real issues, Mora’s submission mainly uses the old guilt-by-association technique that former-disgraced U.S. Sen. Joseph McCarthy used when he suggested that if you know a communist, then you must be a communist too.

One example of this is the absurd link Mora draws between me and Michael Hart who, according to Mora, is a “white nationalist” based on a 2007 book Hart authored. The purported link is that Hart and I co-edited a book titled “Extraterrestrials, Where Are They?”

But our book was the outcome of a meeting we organized in 1979 on prospects for finding extraterrestrial intelligence. The two editions of our book were published by Pergamon Press in 1982 and by Cambridge University Press in 1995. In other words, Mora is holding me responsible for views expressed by Hart 28 years after our initial collaboration. Moreover, contributors to our book included some of the outstanding scientists of the latter half of the 20th century, such as physicist Freeman Dyson, biologist Ernst Mayr and UCLA’s own Jared Diamond, a biologist.

Does Mr. Mora propose that these and other contributors are tainted by a book Hart wrote decades after the 1979 meeting?

Another absurd example of guilt by association involves John Tanton. Contrary to Mora’s claim, Tanton is no friend of mine; we have met exactly once. Mora claims Tanton was involved with me in an internal Sierra Club battle over U.S. population growth. The Sierra Club is the oldest and, arguably, the best-known environmental advocacy organization in the U.S. In 1996, when the club’s board of directors took a position that effectively ignored continuing U.S. population growth, I co-founded Sierrans for U.S. Population Stabilization, composed of Sierra Club members who believe U.S. overpopulation is a serious environmental issue that must be addressed. Tanton was not a member of SUSPS and, for all I know, may not even have been a Sierra Club member during those years. He played no role in the decade-long battle I took part in.

And, finally, to answer Mora’s claims at the end of his submission: Deferred Action for Childhood Arrivals is of interest to many UCLA students. Californians For Population Stabilization currently has no official position on DACA legalization – this “no position” was affirmed at a meeting of the board of directors in early October. DACA legalization is embedded in a suite of proposed bills currently being considered in Congress. One such bill would involve E-Verify, a program that requires employers to verify that a prospective employee is eligible to work in the United States.

My personal opinion is if Congress passes appropriate bills – including, for example, a mandatory nationwide E-Verify that would discourage adults with small children from illegally entering the U.S. in the future – I would be happy to see current DACA immigrants put on some path to naturalization.

Demonization of one’s opponents engenders hate and negates any chance for reasoned discussions. Social justice advocates and environmentalists must find a way to abandon adversarial positions.

Zuckerman is a research professor and professor emeritus at UCLA’s department of physics and astronomy.