I is what I perceived to be your question when you asked how many numbers it would take. The number of like minded justices is the only number that counts. And I think YOU know that.
Not at all.
The number of justices presupposes electing a president who will nominate them, and enough of a willing majority in the Senate to confirm.
So I ask again, what's the bullet-proof number we have to elect to strike down Roe by your plan?
Surely you recognize that number MUST be our requirement if we are to achieve an end to abortion by the only method you seem to approve.