Kudos to Gwen Ifill for asking questions about Darfur and climate change at last night's debate. Darfur in particular was a pleasant surprise. It's very easy to let the genocide fade from the campaign as it falls out of the news and economic anxiety mounts, so putting it on the agenda for a nationally televised debate was an important and deliberate decision. Notice the streaming line graph at the bottom of the screen gauging approval ratings among undecided voters -- they respond overwhelmingly to the call for action to stop the slaughter.

Next week, let's have some questions about climate change as a moral issue. The policy questions are most important, but these debates are also a teachable moment for the American public about climate change's catastrophic, disproportionate impact on the world's most vulnerable people.