PAM Recipe to Authenticate on Either the User's Password or Root's Password

[Schlaegel]

I want 'sudo' to work so that the root password will always work, but
if a user is a member of 'wheel' then their password should also work.

I don't believe that the 'sudoers' file can accomplish this, but I
assume that the Swiss Army Knife of Linux authentication known as PAM,
can.

Do any of you experts know a solution? I must admit that so far I
don't truly grok PAM.

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PS.
If anyone has a desire to argue over 'sudo' vs. 'su' then please start
your own thread. Thank you.