According to Democratic Party rules, a candidate must draw at least 15 percent at each caucus site for the votes to count; if that fails to happen, their supporters often throw their votes to a more viable contender. Combining the second-choice picks of candidates outside the top three, 34 percent would select Obama, 28 percent Edwards and only 15 percent Clinton ...
Among Edwards supporters, 43 percent said they would make Obama their second choice.
Details here. This is encouraging:
Obama is running even with Clinton among women in Iowa, drawing 32 percent to her 31 percent, despite the fact that the Clinton campaign has built its effort around attracting female voters.
Obama has made key gains. His support is up 8 percentage points since July among voters aged 45 and older who comprised two-thirds of Iowa caucus-goers in 2004.