Sen. Elizabeth Warren edged former Vice President Joe Biden in a new poll of voters released a day ahead of Democrats' next presidential debate. The Quinnipiac University national poll showed Warren with 30% of the vote among Democratic voters and independent voters who lean Democratic, and Biden with 27%. Sen. Bernie Sanders trails the two frontrunners, getting 11% support; South Bend, Ind., Mayor Pete Buttigieg is at 8%; and Sen. Kamala Harris at 4% in the survey. Warren and Biden are nearly tied in RealClearPolitics' average of polls.