This is pretty much what the Democrats are trying to do. I remember some Democrat saying basically "We agree with the Church on many issues, possibly more than the Republicans do." If Ratzinger says it "can be permitted," what does that tell you?
HOWEVER!!!! Let's look at that nice neat word "PROPORTIONATE". The Church has done everything it can do lately to make Catholics understand that the death penalty, social justice, and the socio-economic safety net are not proportionate issues to abortion. Abortion and euthanasia stand atop the ladder because of the fact that they are GRAVE SINS that cannot be allowed for any purpose. The Church grants that States have the right to capital punishment (even though the Church is clear that it doesn't think that there is adequate reason in today's Western Culture). But, they do acknowledge the right. There is a right to defend yourself in war. But there is never an allowance for the murder of the unborn and elderly. Ratzinger is not saying it can be permitted!! We have to understand that abortion would never be an equal issue; therefore, a Catholic can NEVER vote for a pro-death, baby killing candidate.
In Europe, say the Cardinal's native Germany, there is no such thing as a prolife candidate.
There are candidates who support only first trimester abortions and there are candidates who support third trimester abortions.
Who do you vote for? By the idea of "proportionate reason" you vote for the former since fewer abortions will likely occur if they are legally restricted to the first trimester.