They are valid as instructions/orders to Executive Agencies but still can violate existing law, and they are valid as a clarification to existing law. Vastly rewriting or undermining the meaning of existing law isn’t within its purview.
No doubt he will claim his order are legal; it is up to a Republican House and Senate to cut him off at the knees as to any money he wants to spend to do it. Cut it to the bare bones only for essential ‘listed’ services. Cut it all off.
My first action as a Republican (Conservative) President would be to UNDO anything he has done, and that includes invalidating any EO he has signed as well as immediately firing any political appointee, Cabinet Secretary, Agency head and EVERY US Attorney in the country.
It’s not a law it’s a REGULATION in HUD