An important perspective to consider on the question of whether pro-abortion politicians should receive communion is the teaching of Jesus about the need to reconcile with our brothers and sisters before coming to the altar.
23 "Therefore, if you are offering your gift at the altar and there remember that your brother has something against you, 24 leave your gift there in front of the altar. First go and be reconciled to your brother; then come and offer your gift.
Those who allow abortion are not reconciled with their unborn brothers and sisters. To fail to see the equal dignity of children in the womb with children outside the womb is prejudice. To consider the unborn as "non-persons" and unworthy of Constitutional protection is an insult. And to consider one’s unborn brothers and sisters as "tissue" or "parasites" is name-calling of the worst kind.
Those who do this have to go first and be reconciled with their unborn brothers and sisters before they can present their gift at the altar.
Communion is bestowed in the context of the Sacrifice of the Mass. That sacrifice is not only the sacrifice of Jesus, but of each of us along with Jesus. We offer him everything – our thoughts, our opinions, our relationships, our choices. We bring our gift to the altar, because we want to be reconciled to God. But those who want to be one with God must be one with their neighbors – all of them.
To be reconciled with our neighbors, we first have to recognize them. The command "Love your neighbor as yourself" actually means "Love your neighbor as a person like yourself." Recognize that no matter how different your neighbor may seem, he or she has equal dignity to you, and therefore demands your respect and love. Failure to protect the unborn is rooted in the failure to recognize them, which is the most fundamental kind of failure to love. The abortion controversy then becomes a matter of expressing beliefs rather than stopping bloodshed.
To be reconciled with our neighbors, furthermore, we have to respond appropriately to their needs. "How can God’s love survive in one who has enough of this world’s goods but turns his back on his brother when he sees him in need?" (1 Jn. 3:17) Is there anyone more in need than the child in the womb? Is there any need greater than to have one’s life saved from a lethal threat?
To be reconciled to our neighbors, we must avoid false witness. To hold, in word or action, that the unborn are of less value than the rest of us, is to "bear false witness against your neighbor." If we are doing that, we are not ready to present our gift at the altar.
Communion means union, and union requires reconciliation. This applies to every citizen. How much more does it apply to those who, as public officials, have the opportunity to pass laws that either grant or remove protection from their most vulnerable neighbors?