Well said, and I'm sorry you had to deal with such a heartless reply.
Let’s remind him:
The USA is built on immigrants and that’s what made this country successful in the first place. Nearly everyone in this country is an immigrant or a direct descendent of immigrants except for the native Americans who are the only non immigrants in this country.
Second, this country would not survive without the work of immigrants or foreign workers. And if those foreign workers would not have a path to citizenship they would go some other place. I work with brilliant Indian IT workers on various visas for work, and if there is no path to citizenship for them then the incentive to work for the US is very small. All of them use their brains, taxes and spend most of their earnings in the US economy. Imagine what blow to the US Economy would be if they all left to some other place...
In reality it’s not anti-immigration that is a bigger issue than racism and bigotry
But… if some are a drain on your limited resources, unhealthy competition for your most vulnerable, or just plain dangerous to your values, then you need immigration laws.
Which is what pretty much every country on earth has concluded. Even the poorest.
There's a drain on limited resources but the idea in America was to attract all the talent and this resulted brain drain in other places, which for a US was a winning point. So, maybe this is a good thing, for other countries??
And let me remind you the real reason the limited resources are being drained the most: the rich eschew their taxes through tax heavens and what not. It is easy to blame it on immigrants to move the attention away from the tax loopholes and other shenanigans the super rich are doing.
This is not something to repeat.
It never goes well for the population already there.