Read full ABC News/Washington Post poll

Among likely voters in the Democratic primary, Clinton has 35 percent support, Obama 29 percent, John Edwards 17 percent and Bill Richardson 10 percent, with others in the low single digits. That compares to a 30-26 percent Obama-Clinton race in Iowa in an ABC/Post poll there two weeks ago. Among the one in four likely voters who say there’s a good chance they may change their minds, 23 percent currently support Clinton, 36 percent Obama, making him more vulnerable.