I think they are way way too many foreigners in US technical jobs. Too many going to our colleges & universities and too many teaching there. All living well at US taxpayer expense. (Yes, I know they pay out-of-state tuition but there is still a considerable government indirect subsidy supporting them particularly since they occupy a slot created and paid for originally by the taxpayer!)
Our current culture and poor K12 system has turned the battlefield over to them? I know & watched two kids leave physics & EE (too hard, too much work!) switch to environmental science (still too hard too much work!) then switch to eSports Business & Entertainement. (Can you believe there is such a curriculum? A degree in becoming a couch potato!) At no point did they calculate that there was too much foreign competition!
central_va I think your current employment problems if you have any or had had any have more to do with you being you then any competition from any foreigner!