Are you saying that legal immigrants are the same thing as illegal immigrants?
Or that Washington is filled with illegal immigrants?
I've not asserted anything about immigrants -- illegal or legal. I asked a non-rhetorical question and I provided my own direct answer to it.
I mentioned D.C. because I live in D.C.; I didn't note that point of fact in the OP. I should have so that the contextual significance of my statement about "tons of immigrants" living in D.C. was clear. That is my mistake.
I gave an answer. Here it is again.
If oversupply of labor in the work force is such that demand drops and price (wages) drop, how is someone supposed to directly see that?
If the guy that got the job you wanted is only applying for that job, because his old job was given to a cheaper illegal worker, how would someone see that?
ect. ect. ect.