I’ve never heard a legal scholar say a legislative act can become law without a presidents signature.
An auto pen is not a presidential signature.
Maybe it has happened, but if anybody wants to challenge it, I can’t imagine a Justice saying an auto pen satisfies the constitutional requirement of a presidential signature. This would be especially a problem if the president was not personally at the auto pen controls.
Show me where the Constitution requires a signature for a pardon. I'll spot you the provision:
Article II, Section 2, Clause 1:
The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices, and he shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment.
There
is a requirement that the President "sign" a bill into law in Article 1, Sec. 7. So the fact that a specific reference to a signing in the document in another place, but not here, is good textual evidence that Art. II, Sec. 2 does not require a signature.
Historical precedent has already been provided.
I can't think of a structural argument other than the one I outlined above re separation of powers on who determines how a pardon is issued--a core Presidential power. In fact, there's a DOJ opinion from the Bush administration that finds the use of autopen legitimate even for the Art. 1, Sec. 7 signing requirement.
Doctrinally,
In Re De Puy (1869) is the only one close, and it says that once issued, a pardon may not be revoked: “The law undoubtedly is, that when a pardon is complete, there is no power to revoke it, any more than there is power to revoke any other completed act.”
I'd win 9-0 and might get you sanctioned.
Legal scholars say that the Constitution doesn’t require a pardon’s direct human signing, and subsequent judicial decisions and legal memoranda support an autopen’s use for similar purposes.
www.pbs.org
ETA: I didn't include prudential arguments which would just be gilding the lily.