Please. Go ahead and contradict him. Tear his arguments to pieces. Propound counterarguments.
[W]e believe that Catholic judges (if they are faithful to the teaching of their church) are morally precluded from enforcing the death penalty. This means that they can neither themselves sentence criminals to death nor enforce jury recommendations of death.
However, the statement is irrelevant to the matter at issue, which is whether one appointed to the Court would hew to the Constitution: an Associate Justice of the Supreme Court would not be in a position to sentence criminals to death nor to enforce jury recommendations of death.