Voting for a pro-abortion politician should be a mortal sin.
Voting for a pro-abortion politician always has been a mortal sin as long as the necessary knowledge and consent is given in the commission of this sin. The current crop of politically correct, progressive bishops have just refused to enforce or teach that fact for decades.
According to my priest, it is. You can be an accessory to sin even if you didn’t commit the sin. If you know a politician is pro-abortion, and you willfully cast your ballot for them, you are an accessory to that sin.
From the Catechism:
1868 Sin is a personal act. Moreover, we have a responsibility for the sins committed by others when we cooperate in them:
- by participating directly and voluntarily in them;
- by ordering, advising, praising, or approving them;
- by not disclosing or not hindering them when we have an obligation to do so;
- by protecting evil-doers.
This is summarized by the nine ways of being an accessory to sin:
1.By Counsel
2.By Command
3.By Consent
4.By Concealment
5.By Defense of Evil Done
6.By Partaking
7.By Provocation
8.By Praise
9.By Silence