The Iowa Democratic Party has been preparing for record-breaking turnout for more than a year, driven both by Democrats’ angst about President Donald Trump and by an unusually large field of candidates — many of them with their own significant, independent turnout operations. The state party chairman, Troy Price, said the party is anticipating more caucus-goers than in 2008, which set a record when 239,000 Democratic voters participated, lifting Obama to victory.

“The winner is always who’s bringing a bunch of new [voters], said Sue Dvorsky, a former Iowa Democratic Party chairwoman who backed Sen. Kamala Harris before she dropped out of the race.

The difficulty this year, she said, is that new voters could go to any number of different candidates. “There literally is no historical analogy here,” she said.

Every candidate could see potential advantages in a high-turnout caucus. And the weekend saw each of them working furiously to swell their lanes of support.