The Wikipedia explanation of when a Corporation is – and is not a person has some good bibliography. Essentially, though, a “legal fiction” is when due to case law or settled custom, courts and government pretend something untrue is true.
Note that the Wikipedia entry had not been updated, and predicted/considered that corporations and similar entities are neither entitled to, nor should they be entitled to free speech protections.
In fact, the USSCT created this doctrine in 1883, in the Santa Clara County decision, see discussion of Santa Clara County decision Apparently, Court Reporter J.C. Bancroft, in pre internet days, added language into an official report which is the entire genesis of the corporate personhood legal fiction, and the new, repugnant Citizens United decision.
Therefore, if a “Defense of Marriage Act”, or “DOMA”, can define marriage as being a legally recognized union between a man and a woman – without amending the constitution, why can’t a “person” be defined by legislation as “live flesh and blood human being, who is currently alive” for purposes of entitlement to constitutional rights, such as “free speech” from the Bill of Rights?
My preliminary analysis says this WOULD work; i.e., the cumbersome process of amending the U.S. Constitution is NOT needed, but rather an amendment to the United States Code, by passage of legislation such as was done in DOMA.
Shall we call it the Defense of Humanity Act or DOHA?
To allow corporations to pour their greater concentrated capitol directly into the political process is to return to the days of J.P. Morgan and the Rail Road Senator in Congress.