A priest in a homily said that if you vote for a pro-abortion candidate you should not go to communion.
Worthiness to Receive Holy Communion: General Principles
Cardinal Joseph Ratzinger
Prefect, Congregation for the Doctrine of the Faith
A Catholic would be guilty of formal cooperation in evil, and so unworthy to present himself for Holy Communion, if he were to deliberately vote for a candidate precisely because of the candidate’s permissive stand on abortion and/or euthanasia. When a Catholic does not share a candidate’s stand in favour of abortion and/or euthanasia, but votes for that candidate for other reasons, it is considered remote material cooperation, which can be permitted in the presence of proportionate reasons