You cannot honestly think the Vatican is capable of tracking down every offender worldwide and issuing decrees of official excommunication.
This form of excommunication is spelled out plainly in the catechecism.
It holds true for those who have committed grave sin and have not repented.
Any catholic who isn’t aware of this does not know much about their own religion.
Whether or not this is incentive for a heretic politician is the problem of the politician.
In the end, he/she is the one who has to answer for their actions.
If they want to try and win catholic votes while promoting abortion and still insisting on presenting themselves for communion - then that is a serious issue they will have to deal with the ultimate judge.
there are many catholics who sit their fannies in the pew on sundays during communion knowing they shouldn’t receive until they’ve confessed.
It would take many letters, a good volume of office supplies, and a couple hours a week from every priest.
A very high percent of offenders could be given the chance to recant, or else suffer some degree of shame and humiliation for quarreling with their own chosen faith.