This week, Congress sent President Bush a bill easing restrictions on federal funding for embryonic stem cell research, but so far Bush isn't in a big rush to veto the bill as promised. Bush did say the bill "puts scientific research and ethical principle into conflict" rather than providing "a balanced approach that advances scientific and medical frontiers without violating moral principles." Stem cell research is among the president's least favorite issues. It's too fraught and ambiguous and lacks the clear political and moral distinctions that he prefers. As with the clean air issue, Bush is hoping technology and private...