In the new poll, Cain edges Romney 23-22% with Ron Paul the only other candidate in double digits with 12%:

Cain has surged 13 percentage points since the first Iowa Poll of the caucus cycle, conducted in late June. His rise has come despite spending little time in Iowa recently, campaigning here just once since the Aug. 13 Iowa straw poll, where he placed fifth.

Likewise, Romney has campaigned in Iowa just three times this year, but he retains a core network of supporters from his near-constant presence in the state during his first presidential bid four years ago.In the new poll, Congressman Ron Paul of Texas is the only other candidate in double digits, in third place with 12 percent.

The Iowa caucuses are scheduled for Jan. 3. The Iowa Poll, a Register exclusive since 1943, is a much-watched indicator of how candidates are faring in the nation's leadoff caucus state.

Minnesota Congresswoman Michele Bachmann, winner of the Iowa straw poll, has seen her popularity wane. In the June Iowa Poll, she enjoyed support of 22 percent of respondents, trailing poll leader Romney by a single percentage point. She has dropped to 8 percent and fourth place in the new poll.

Gingrich and Perry are tied for fifth with 7% while Rick Santorum, who has criss crossed the state several times, is at 5%.

Romney doesn't have to win Iowa - but he can't get blown away. There will probably be one week less to recover this year due to the compressed early primary schedule and any sign of Romney weakness in Iowa - a distant second or third place finish - would make New Hampshire a horse race.

Cain, meanwhile, is marching to his own drummer. He is slowly building an Iowa organization but is a long way from competing with the Bachmann or Romney operations. He may be counting on general enthusiasm for his candidacy to move people to the caucus sites on January 3 - a risky but sensible strategy given the time limitations involved.