The upper midwestern state of Iowa is set to start the 2020 US election voting cycle in the Democratic Party on Monday to pick a candidate to run against President Donald Trump.
The battle to win the largely rural Hawkeye state in 2020 is highly contested between the top four candidates: former vice president Joe Biden, leftist Senator Bernie Sanders, Senator Elizabeth Warren and former Mayor of South Bend, Indiana, Pete Buttigieg.
The latest CBS-YouGov poll released on Sunday showed a tie between Mr Sanders and Mr Biden at 25 per cent, while other polls such as Emerson had the Vermont senator in the lead.
Betting markets including PredictIt are projecting a win for Mr Sanders.
A notable absence at the Iowa caucus was billionaire candidate Michael Bloomberg, who was on the other side of the country in California.
Mr Bloomberg's campaign will forgo early voting states and concentrate on California, Texas and other battlegrounds to come.
The voting process in its caucus adds to the unique nature of Iowa.
Voters gather in schools or stadiums across the state and declare their choices publicly instead of casting a secret ballot.
There are also two rounds of votes. The first will include all 10 Democratic candidates while the second will eliminate anyone below the 15 per cent threshold, whose supporters get to pick a second choice.
The top four candidates with the highest number of votes will be allocated a delegate count that they will carry to the Democratic convention in July to officially pick a nominee.
The opinion poll analysis website Five Thirty Eight showed a heated race between the top four candidates.
It said these were the most contested Iowa caucuses since 1980.
“We found that the 2020 contest not only has the largest number of contenders within 10 points of the polling leader, but also is tied for the most candidates polling at or above 15 per cent,” the website said.
But as they scrambled to the finish line, top Democratic candidates chose highly different strategies.
Mr Biden’s message focused on the electability card while his closest rival Bernie Sanders stressed his progressive agenda and issues such as eliminating all student debt.
Ms Warren focused her campaign on the Iowa suburbs and the female vote. CNN reported that volunteers from the Warren campaign were offering child care for the caucus night.
Mr Buttigieg has built his campaign on exciting the youth, and using an Obama-like message of hope and unity.
A lot will depend on the turnout and the segments of the electorate.
Iowa’s highest caucus turnout was in 2008 when 236,000 voters showed up, giving former president Barack Obama the nomination.
While Mr Biden is hoping for a higher turnout among senior voters, Mr Sanders and Ms Warren are betting on the younger vote.
The results are not expected to start coming in until 7.30pm local time.
A good showing for Mr Sanders will give him momentum before the New Hampshire and Nevada votes, where he currently leads in the polls, this month.
But Mr Biden, whose poll numbers have declined in the past few weeks, will need a good result in Iowa to take the fight to South Carolina, where he is in the lead, on February 29.