You think a Catholic who promotes abortion and is refused Communion is going to keep giving to the Church?
It is because they give GOVERNMENT MONEY to the Church that bishops refuse to deny them Communion.
BTW: Denial of Communion in these cases is NOT OPTIONAL. It is MANDATED by the moral law and by canon law.
http://tinyurl.com/canon915
http://tinyurl.com/pont915
The Holy Bible doesn’t say anything specific about denying communion to church members who show by their actions that they are unrepentant sinners (corrections welcome). But the Bible essentially indicates in Matthew 18:17 and 1 Corinthians 5:11 that church members should not associate with such people.