Last I checked, abortion is taken care of by nothing less than the 10 commandments - i.e. that little provision about not killing. Homosexual intercourse is specifically condemned in both the old testament and in Paul's letters, which are considered to be divinely inspired texts. The fact is that the bible is clear and explicit about both. To pretend otherwise is to fib.
Which, I suppose, would also explain the Church's condemnation of capital punishment. Yet nobody is talking about denying the sacraments to a politician who supports that.
And divorce is specifically condemned in Christ's own words in Matthew and Mark, and those like Kerry (or Gingrich and Reagan for that matter) who divorce and remarry are living adulterous lives. Yet we don't condemn those who support divorce. In fact we cheer them on as they make divorce easier and provide tax incentives for those who destroy their families. So by all means deny those who support abortion rights access to Communion, I don't have a problem with that. But advocate the same for those who support other positions that are contrary to church dogma, like capital punishment and divorce. It's only right, wouldn't you agree?