H1-B workers are Legal. It is creation of your elected politicians supported by big outfits such as Amazon, Microsoft, Walmart, Google, etc. Those outfits are making big profits using cheaper labor from H1-B workers. The big corporations are big political donors. Peons like me and you have no power except vote for some different politicians. But politicians survive with donations.
On the positive side, H1-B workers have the lowest crime rate , lowest welfare (actually none are eligible) compared to any other group.
H1B visa holders ACT AS invaders, regardless of legality. I oppose the entire system.
Defending something solely on the basis of legality is a bit misguided. Keeping people as chattel was once legal. Putting subhumans (lit: under-men) in concentration camps was once legal. Slaughtering babies in utero currently IS legal ... even constitutionally protected in some States.
your elected politicians
It seems to me that an actual American who votes would describe those creatures in Washington as "OUR elected politicians".
On the positive side
There isn't one.