I haven't found any reasoning behind this yet, so race is really the only logical possibility.
...or they are tired of people taking advantage of the system.
I just wish these debates didn't become "You want to change the law because you hate brown people."
Same, no other nation of the world with a similar degree of power as the United States allows children born on their soil to automatically become citizens. Too many people abuse the system now with the intent of staying on American soil because their children were born here.
A list of all nations of the world with a similar degree of power as the United States (excepting the US):
{}
Now, it's well established mathematically that {} is a subset of any set. Thus,
{} is a subset of {nations which allow children born on their soil to automatically become citizens}
Therefore your first sentence is flat wrong. In fact, all nations with a similar degree of power to the US have birthright citizenship.
As for your abuse of the system line: you're a parrot repeating a talking point unless you can find me an estimate as to how much it's costing us.
