The canonical basis for who may vote in a papal (Roman Pontiff) election is twofold: (1) the Pope’s authority to select and create cardinals before a vacancy, and (2) the rule that the electing body is the College of cardinals, but with specific legal qualifications (e.g., publication of the creation, loss of the office, age limits). 1 2 3

The legal structure: cardinals are the electing body, by “special law”

Canon law states that the College of Cardinals is a special body that “provides for the election of the Roman Pontiff according to the norm of special law.” 1

That “special law” is principally the Apostolic Constitution Universi Dominici Gregis, which reiterates that the electors are only the Cardinals of Holy Roman Church. 3 4

How the Pope “selects” who can later elect: creation of cardinals

The Pope’s free choice and the required qualities (CIC 351)

The Code of Canon Law makes the decisive point that the Roman Pontiff freely selects men to be promoted as cardinals. 2

But it also sets objective criteria for suitability: the candidates must be:

• ordained at least to the presbyterate; and
• “especially outstanding in doctrine, morals, piety, and prudence in action”; and
• if not yet bishops, they must receive episcopal consecration. 2

So, the canonical basis for “cardinal selection” is: Papal appointment guided by concrete moral, doctrinal, and pastoral qualities. 2

The Pope’s right to adapt the election framework

Universi Dominici Gregis explicitly teaches that it is an “indisputable principle” that the Roman Pontiff has the right to define and adapt the manner of designating the person called to succeed Peter, including the body entrusted with the election—while maintaining faithful continuity with tradition and canon law. 3 4

This provides the deeper canonical rationale: the constitution and the election norms depend on the Pope’s lawful power to structure the electing college (through the creation of cardinals). 3 4

Publication matters: created vs. created “in pectore”

Cardinal-elector participation is not automatic upon a private intention.

• Canon 351 §3: if the Pope announces a selection “in pectore” (keeping the name reserved), the person is not yet bound by the duties and does not possess the rights of a cardinal until the name is published. 2

• Universi Dominici Gregis clarifies the election consequence: a cardinal has the right to elect the Pope only if he has been “created and published” before the College of Cardinals. 5

So the canonical logic is consistent:

Who counts as an elector at the conclave

Creation and publication, even without the red hat/ring

A cardinal of Holy Roman Church who is created and published before the conclave has the right to elect, “even if he has not yet received the red hat or the ring” or sworn the oath. 5

Thus, canonically, elector status turns on the juridical act of creation with publication, not on ceremonial tokens. 5

Exclusions: deposed or renounced cardinals

The right to elect is denied to cardinals who are:

• canonically deposed, or
• who have renounced the cardinalate with the Pope’s consent. 5

And during the vacancy, the College cannot “readmit or rehabilitate” them. 5

Age restriction and numerical limit (as part of determining the electing college)

Universi Dominici Gregis confirms the longstanding rule that the cardinals who have celebrated their eightieth birthday before the day the Apostolic See becomes vacant do not take part in the election. 3

It also confirms the maximum number of 120 cardinal electors, aiming to express the Church’s universality while managing the burden of choosing the Pope. 3

Assessment: what the “canonical basis” implies about cardinal selection

Putting these norms together yields a coherent canonical principle:

1. The Pope’s “free selection” of suitable men into the cardinalate (CIC 351) is the principal mechanism by which the electing body is constituted. 2
2. Elector eligibility depends on juridical publication and persistence of office, not on ceremonial reception (red hat/ring) and is lost if the cardinalate is renounced or deposed. 5 2
3. The Pope also lawfully limits the electing college through rules such as the 80-years cutoff and the general maximal size of electors, which Universi Dominici Gregis confirms. 3
4. The Church’s system is therefore not “selection by the electors” but selection by the reigning Pope for a future conclave, while the election itself is reserved to the canonically defined college. 1 2 3

In short: canonically, cardinal selection is the Pope’s lawful appointment process, and it only becomes decisive for a papal election insofar as it creates (and publicly publishes) an eligible group of cardinal electors under special law. 1 2 5 3