Republican front-runner Donald Trump is in for he’s first real test on Monday when Iowa voters begin the nationwide process of choosing a new U.S. president.
Polls are currently showing a tight battle between Ted Cruz and Trump that. On the Democratic side, Hillary Clinton also faces a tough challenge in Iowa from Bernie Sanders.
Late polls showed that Trump has a small lead on Cruz, while Clinton had a slight edge on Sanders, a U.S. senator from Vermont. But there was no certainty on who would turn up at the caucuses, or how successful Trump and Sanders would be at getting participation from supporters, many of who are new to the process and disenchanted with traditional politics.
Adding to the unpredictability in Iowa was a large bloc of undecided or persuadable voters in both parties. People in the state are accustomed to a long courtship from candidates and are traditionally in no rush to make a commitment.
Iowans will begin choosing candidates at 7 p.m. CST (0100 GMT on Tuesday), with results expected within a few hours. The caucuses will be the first time Trump, a real estate mogul and former reality TV star, has put his appeal to the test.
A win could validate an aggressive campaign that has alarmed many in the Republican establishment, dwarfed the campaigns of many seasoned politicians and has been marked by controversies such as his calls for a temporary ban on Muslims entering the United States and for a wall along the Mexican border. It would put him in a strong position for later nominating contests.
A loss for Trump would dent his self-identity as a winner and create immense pressure for a better performance in the next contests - in New Hampshire on Feb. 9 and South Carolina on Feb. 20. Trump said he was confident that Iowans who have attended his rallies in large numbers would turn out for him on a wintry evening on Monday.
"It's been an amazing journey, and there's a lot of love in those rooms so I would think that they would show up to vote, I hope so," he told NBC's "Today" program.
The Iowa caucuses give the Midwestern state a political influence far greater than its small size and kick off a primary process that leads to the parties' formal presidential nominations at summer conventions.
The caucuses are a long and sometimes arcane ritual, taking place in 1,100 schools, churches and other public locations across the Midwestern state. At least two Republican caucuses will be in private homes and one Democratic caucus will take place at an equestrian center.
White House hopefuls descend on the state early and often and give people the chance to see them up close, making many Iowans slow to decide who to back.
"I'm still checking them out. The field is large and it requires some thought," said Paul Albritton of Carlisle, Iowa, a training coordinator at Iowa State University, as he waited to see U.S. Senator Marco Rubio of Florida last week. "I'm thinking about who can win in November."
For the winners in Iowa, the prize will be valuable momentum in nominating battles that could stretch for months, while many of the losers on the Republican side could quickly begin dropping by the wayside.