DES MOINES, Iowa, Dec. 30 (UPI) -- Observers watching the Democratic presidential race in Iowa say it's one of the most costly in Iowa caucus history as rivals dig deep for new voters.

Sens. Barack Obama and Hillary Clinton scoured Iowa in search of new supporters in the caucus process, while former Sen. John Edwards worked his way through past participants.

New poll numbers show a three-way tie in Iowa between Clinton, Edwards and Obama where the Democratic contest swings on as few as 1,000 out of the estimated 125,000 likely caucus-goers, The New York Times (NYSE:NYT) reported Sunday.

Clinton and Obama spent lavishly on propaganda from lapel pins, extra-large-type campaign materials targeting elderly caucus-goers and even sandwich platters to entice people.

Obama even promised to find baby-sitters to persuade parents to show up Thursday night.

Clinton and Obama employed complex demographic and consumer data analysis employed by the Republican National Committee in 2002 to find potential supporters in Iowa.

Edwards' campaign, however, expressed hesitation that strategy would make a significant difference.

"Iowa voters are not going to say, 'Oh my God! I got a bumper sticker. I should caucus!'" Jennifer O'Malley Dillon, Edwards' Iowa campaign manager told the Times.