From The Corner at National Review Online:

On the one hand, the results look encouraging for Giuliani – 64 percent said his views on abortion and gay rights would either make them more likely to vote for him or make no difference. But that 21 percent for whom it would make them more likely to vote against him is a pretty big number. And in perhaps the most important finding in the poll, Gallup also asked Republicans and Republican leaners whether Giuliani is “generally pro-life or pro-choice, or are you unsure?” Eight percent said Giuliani is pro-life, 37 percent said pro-choice, and 55 percent said unsure. Those numbers are a change from January, when 16 percent said Giuliani was pro-life, 20 percent said he was pro-choice, and 64 percent weren’t sure. It could be that the voters for whom that matters greatly already know Giuliani’s position, or it could be that that 55 percent includes voters who will turn against him once they learn more about him.

If more than half of Republicans surveyed “don’t know” Mayor Giuliani’s position on life, but will certainly learn as primaries come nearer and nearer, this might explain his commanding lead that is confusing to some, and how easily it can (and will, in my opinion) slip away.