DES MOINES, Iowa, Jan. 31 (UPI) -- The final poll before the Iowa caucuses shows former Secretary of State Hillary Clinton leading Vermont Sen. Bernie Sanders by just 3 percent in the Democratic race, with high turnout making a Sanders win more likely.
The Des Moines Register/Bloomberg Politics poll of 602 likely Democratic Iowa caucus-goers showed Clinton had 45 percent to Sanders' 42 percent, with a margin of error of plus or minus 4 percent, meaning the two candidates were statistically tied.
"It comes down to who can grind it out on the ground on Monday night," David Axelrod, a national political strategist, told the Register. "Turnout is everything. If turnout is within a normal range, Hillary likely wins. If it goes higher, approaching 200,000, it will be a good night for Bernie."
"If people come out to vote, I think you're going to be looking at one of the biggest upsets in modern political history," Sanders said on CNN's State of the Union with Jake Tapper on Sunday morning.
The Sanders surge might come as a surprise to many, considering the first Iowa poll had Clinton leading Sanders by 41 percent when both candidates announced their campaigns last year.
According to the latest Iowa poll, Clinton supporters believe the system works reasonably well for people working hard to get ahead, while Sanders supporters believe the system is rigged to benefit the rich and powerful -- creating an establishment vs. anti-establishment scenario.
Clinton has strong support from older caucus-goers, particularly women older than 45. Sanders is supported by 63 percent of caucus-goers under 35 and has strong support from men.
On the question of the candidate who cares most about "people like you," Sanders wins with 51 percent to Clinton's 37 percent.
On the question of whether a candidate is well-liked, 82 percent of people had a favorable view of Sanders, while 81 percent had a favorable view of Clinton.