Joe Biden faces a new threat from South Bend, Ind., Mayor Pete Buttigieg, who is fresh off an eye-opening debate performance and positioning himself to be a top contender for the support of centrist Democrats if the former vice president falters. Buttigieg has emerged as a fundraising powerhouse and will enter the final stretch before the Iowa caucuses in February flush with cash. Buttigieg has more than $23 million in the bank, compared to only $9 million for Biden, a shockingly low number for a front-runner. Recent polls of Iowa show Buttigieg on the rise. The mayor has picked up 4.5 points in the past month in the RealClearPolitics average, and a Firehouse-Optimus survey released this week found him in third place at 17 percent in the Hawkeye State, within striking distance of both Sen. Elizabeth Warren (D-Mass.), at 25 percent, and Biden, at 22 percent.