Understanding the impact of illegal immigration does not depend on accepting partisan opinions. It is just the result of doing some simple math.

In a previous article, Illegals Deadlier Than War On Terror, we compared the numbers of United States citizens killed by illegal aliens to the tally of our troops killed in the war on terror. In response to that article, one of our readers wrote asking whether we had seen the video produced by NumbersUSA titled Immigration by the Numbers. He asked, “I wonder how accurate it is?”

This widely distributed video uses gumballs in a jar to visually demonstrate the impact of numbers that increase exponentially rather than linearly. These are mathematical concepts that are immediately meaningful to folk with a technical background, but may be harder to understand for others. The answer to our reader’s question is that the video IS accurate. It is not based on partisan opinion. It is just a very graphic illustration of an algebraic equation.

You can view a clip from the video here. Roy Beck of NumbersUSA is not depending on any esoteric data. He’s just doing the math, based on the US Census numbers, which actually grossly UNDERESTIMATE the number of illegals in the United States.

The gumball video is just a reprise of that old high school science experiment in which you have a population of fruit flies — Drosophila — that doubles with every generation. (The reason they used fruit flies is that drosophila require only a week to ten days to reproduce, and you can easily get the experiment done during a thirteen week class term.)

You fill the jar 1/8 full with fruit flies. It looks like there is a lot of room left. Next thing you know, the jar is 1/4 full. Then 1/2 full. But not to worry, because there is still half of the whole jar available for them to fly around in. And then — WHOOPS — the jar is jammed full, and they begin to die.

However, in the video, Roy Beck uses gumballs instead of fruit flies.

For a population to grow in numbers, more children must be born than the number that are needed to replace the older folk who are dying. If every man and woman pair off monogamously, and we don’t allow for a slight variation due to women who die before childbearing years, simple replacement requires that every woman have two children (one to replace herself and one to replace her man). If every woman had four children during her childbearing years, the population would double every generation like the fruit flies, sans devastating war, terrible famine and pandemic lethal disease like the black plague.

Mexican immigrant women (legal and illegal) living in the United States have a fertility rate of 3.51 according to the 2002 US census. So their population will not quite double, but it certainly will increase at a very rapid rate. And whereas the educated American population may defer marriage and childbearing until they are adequately prepared to raise a family, the immigrants will produce “anchor babies” as soon as biologically possible, no later than age 18, because we as taxpayers will support them. So our “jar,” the continental United States, will fill up pretty rapidly.

But mathematically it gets worse, much worse. The parents do not die when the kids are born as the fruit flies do. So now within four years, the 2 parents and their 3.51 kids are all living here. Illegals are coming at the rate of about one million per year from Mexico, according to the latest estimates by border patrol agents. So within four years, each annual increment will have become 2,755,000 mouths to feed — the original million plus the 1,755,000 children that the 500,000 women in the increment will have produced.

In less than eleven years, that’s 10% of our current population. And please note, this analysis only includes parents who are ILLEGALS. It does not include anchor babies born to parents who are here legally on work visas, and produce offspring for the sole purpose of staying. It also does not include the huge jump in numbers that will occur eighteen years out, when the children of the illegals start reproducing.

What makes these considerations most galling, however, is the fact that this high birth rate of 3.51 for Mexican women living illegally in the US is evoked by the deep pockets of the American taxpayers. It only occurs in the benevolent social welfare context of the United States. Mexican women living in Mexico have a birth rate of 2.4 children.