"We were all an embryo at one point, and we ought to as a society be very careful about being callous about the wanton destruction of embryos, of life," White House aide Karl Rove told the Denver Post this week. He was explaining why President Bush is committed to casting his first-ever veto against a bill -- which may pass the Senate as early as next week -- that would give tax dollars to researchers who deliberately kill human embryos to extract their stem cells. "The president is emphatic about this," Rove said. This veto threat is necessary because of...