Stem cell research
The Duke has not followed the stem cell research debate in any level of detail. Apart from passing interest that the traditional abortion rights lines have been blurred (e.g., Orrin Hatch's support), the nuances of the debate never provoked further inquiry.
But a recent luncheon with a friend who is close to a Cardinal opened up an interesting area of debate. Apparently Catholic teaching does not require "unnatural" or "extraordinary" means to prolong life. Catholics also encourage organ donation, though there is some debate over when such a transplant is permissible. If it is not a sin to let a loved one die naturally, without the aid of advanced medical technology, then it must hold that it is not wrong to let a frozen embryo expire on its own.
The Duke understands and even shares concerns that unfettered embryonic stem cell research could create perverse incentives to create new "unwanted" embryos. But it is a fact that thousands of those embryos already exist. It is also a fact that most will eventually be destroyed. Why can't people of good faith on both sides of the debate agree that embryos created before any research rules are implemented are perfectly acceptable sources of new stem cell lines?