Many of us would like for this unconstitutional law to be
annulled from the beginning. (and many others) However, The
second sentence of Art 1. Section 7 says...Every bill which
shall have passed the House of Representatives and the Senate,
shall, before it becomes a law, be presented to the President of
the united States; if he approve he shall sign it, but if not he
shall return it with his objections...
If you would read the last part of that sentence where it says
"but if not he shall return it"
if not what? if he does not approve the bill he must return it.
The only stipulation for the return of the bill is if he (the
President) does not approve of the bill.
If he has approved it by signature or the passage of 10 days he
is not required to return it. If he approves the bill it matters
not whether congress is in session or adjourned.