Let us explore the context. First, the bishop addresses the issues of scientific uncertanties regarding beginning of life. Next, he addresses the concerns regarding health care, education, economic security, immigration, and taxes, and finally moral theology of war. It is in comparison to these concerns that the horror of taking an innocent human life stands out. And he explains why:
the solutions to problems in these areas do not usually involve a rejection of the sanctity of human life in the way that abortion does. Being “right” on taxes, education, health care, immigration, and the economy fails to make up for the error of disregarding the value of a human life.[...]
A person who supports permissive abortion laws, however, rejects the truth that innocent human life may never be destroyed. This profound moral failure runs deeper and is more corrupting of the individual, and of the society, than any error in applying just war criteria to particular cases
[...]
The failure to protect life in its most vulnerable stages renders suspect any claims to the ‘rightness’ of positions in other matters affecting the poorest and least powerful of the human community. If we understand the human person as ‘the temple of the Holy Spirit’ – the living house of God – then these latter issues fall logically into place as the crossbeams and walls of that house. All direct attacks on innocent human life, such as abortion and euthanasia, strike at the house’s foundation
It is clear that "precedence over every other issue" is referring to precedence over issues of social policy in front of the voter, and not issues of abstract theology.
Nice try, Alex.
You nailed it.