Hillary Clinton has solidified her lead in Iowa, leading Bernie Sanders by 22 points among likely caucus-goers.
The Democratic front-runner took 55 percent of the vote, followed by Sanders with 33 percent and Martin O'Malley trailing behind at 6 percent, according to the latest Monmouth poll. Among past voters who are considered most likely to turn up on caucus day, Clinton leads by an ever greater margin of 27 points, 57 percent to Sanders' 30 percent.
Turnout in the Iowa caucuses has historically been unpredictable. While 240,000 voters showed up in 2008, when there was a three-way race between Clinton, Barack Obama and John Edwards, it is expected only 100,000 will for the 2016 caucus.