Why didn't Brokaw mention abortion in the debate last night?

This is the question on pro-lifers's minds today after a lackluster debate on the economy and foreign policy. Fr Thomas Berg, LC takes this issue on at National Review Online. My view is that the issue is too damaging for Obama, and we all know that any moderator of a debate has to be a liberal. Who decides that anyway?
Why doesn't McCain get Bill O'Reilly to moderate, and invite Obama publicly?

Maybe I just don’t get it.
As many otherwise pro-life Catholics voting for Obama this time around might want to remind me, “it’s the economy, stupid” — now more than ever, right?
Indeed, the common wisdom appears to be that in election 2008, the economy trumps every other issue in urgency and magnitude — even abortion. If pro-lifers think the pro-choice, pro-Freedom of Choice Act, pro-partial-birth-abortion candidate is more qualified to handle America’s looming economic disaster, why should they hesitate to vote for him?Catholic bishop Joseph Martino of Scranton responded to this logic in his pastoral letter for Respect Life Sunday (celebrated on October 5th this year in all Catholic parishes in the United States):
This reasoning is sound only if other issues carry the same moral weight as abortion does, such as in the case of euthanasia and destruction of embryos for research purposes. Health care, education, economic security, immigration, and taxes are very important concerns. Neglect of any one of them has dire consequences as the recent financial crisis demonstrates. However, the solutions to problems in these areas do not usually involve a rejection of the sanctity of human life in the way that abortion does.