So, yes, we oppose the death penalty in that we hold all life to be sacred, but we realize also that in some circumstances it may be deemed necessary. But Catholic teaching can never weigh opposition to capital punishment the same way it does to abortion. The thousands of innocent pre-born babies killed every year by abortion constitute a much greater evil than the number of executions of convicted criminals by the state, not only because of the sheer number of deaths but because of the gravity of abortion itself. Abortion, unlike capital punishment, is an intrinsic evil and can never be justified.
No candidate is going to be perfect. Even in voting for one who does not fully represent our beliefs, we are not compromising our ultimate goal, which must be the protection of all human life, especially pre-born children. Voting for a certain candidate does not mean that we endorse his positions on every issue. We have a duty to use our vote to advance the common good.