For example, mean pay for a software developer in state of California is $119,970 according to Bureau of Labor Statistics [1]. What is the minimum wage required for a H1B software developer in California [2]? What is the actual mean pay?
My instinct is that you are correct and H1B visas are not driving down salaries- but thats just a guess, I have no idea. But your arguments so far are "dont be a bigot" and "its all public information".
If its public information, have you seen it? If so, share it with us. If not, how are you sure you are correct?
If you are just venting, then vent away my friend.
Otherwise, it is ineffective to fight bigotry by telling people they are bigots. Share data from a trusted source, give sound analysis, and hope for the best.
Good luck.
1. http://www.bls.gov/oes/current/oes151132.htm
2. I would have dug this up myself but its actually a bit of work to compile as a meaningful look at this issue requires looking at many geographical areas and professions.