Former Vice President Joe Biden is leading in a new poll of likely Iowa Democratic caucus-goers, with less than a month until the Feb. 3 vote in the Hawkeye State. Biden draws 24% support in the Monmouth University survey, putting him ahead of Sen. Bernie Sanders, who had 18%, ex-South Bend, Ind., Mayor Pete Buttigieg, with 17%, and Sen. Elizabeth Warren, who pulled in 15%. Biden and Sanders have both gained five points since the November poll by the same university. An average of recent Iowa polls shows Biden and Sanders essentially tied in the state.