I have seen several excommunications over the years. They're necessary in cases of gross public sin. If this isn't gross public sin by publicly threatening to persecute the church of which you are theoretically a member,what else could possibly qualify?
I suspect the idea was to avoid making a “martyr” of this woman by simply advising her of the canon law on the matter regarding automatic excommunication, thereby avoiding drawing sympathy toward her as a “victim.” Maybe that's okay with a pro-choice politician who doesn't make a big deal of his views.
Well, this woman not only makes a big deal of her views but threatens to persecute her own church. Time to respond with a formal public excommunication. Most secularists who are fair will understand private organizations can set their own membership rules, and this woman did take on her own church in public, so she isn't a good example of a victim.
Avoiding making martyrs out of the likes of Sebelius, John Kerry, et al., has not worked. They should be splashily and publicly excommunicated.
Your point about secularists who are fair is particularly well taken.