The top three Democratic presidential contenders remain locked in a close battle in Iowa, with Sen. Barack Obama drawing support from 30 percent of likely Democratic caucus-goers in Iowa, compared with 26 percent for Clinton and 22 percent for former senator John Edwards. New Mexico Gov. Bill Richardson received 11 percent. The results are only marginally different from a Post-ABC poll in late July, but in a state likely to set the tone for the rest of the nominating process, there are significant signs of progress for Obama -- and harbingers of concern for Clinton.
