“can you be both for protecting the borders and then show chessed and hire those who are here and do honest work?”
No, absolutely not.
“You are not supporting criminals”
Illegal immigration is a crime. There is no such thing as an illegal immigrant who isn’t a criminal. Yes, you are supporting criminals if you harbor illegals; you just happen to be okay with the crime so you wish to pretend otherwise.
When a drug addict buys cocaine from an illegal working for a cartel, they’re also doing their own “vetting.” They just have different standards than you regarding what is and isn’t okay. They need their fix just like you need your cheap cleaning lady. There’s a reason it isn’t just left up to the individual to do their own heimish vetting process.