Pete Buttigieg has surged into the top three in an Iowa caucus poll, putting him within striking distance of Elizabeth Warren and Joe Biden. The poll, carried out by Suffolk University and USA Today, put support for Biden at 18 percent, Warren at 17 percent, and Buttigieg at 13 percent among 500 likely Democratic caucus-goers. The numbers represent a significant shift from a Suffolk poll taken in June, when Biden had a double-digit lead over Warren and Buttigieg lagged way behind with just 6 percent. Kamala Harris, who placed second in the previous poll, has plummeted 13 percentage points, while Bernie Sanders earned an unchanged 9 percent support. Meanwhile, Bloomberg News reports that Mark Zuckerberg has privately offered help to Buttigieg’s presidential campaign. The Facebook CEO and his wife, Priscilla Chan, reportedly named several potential hires to the campaign manager Mike Schmuhl, two of whom later joined the campaign.