Democratic US presidential candidate Senator Bernie Sanders
Nevada is the first nominating state with a diverse population after contests in predominantly white Iowa and New Hampshire. More than four of every 10 voters in the Nevada Democratic caucuses in 2016 were non-white, according to entrance polls.
Sanders has led national polls among Hispanics, who represented about one-fifth of the Democratic electorate in the 2016 Nevada caucus. In Nevada, Sanders has led the last five opinion polls, taking a lead over moderates Biden and Buttigieg, as well as his progressive ally Warren.
Sanders lost Nevada to Clinton by five percentage points during his first presidential bid in 2016, but this time he faces a far more splintered field that includes three centrist candidates - Biden, Buttigieg and Klobuchar - all vying to win votes of the party's moderate wing.
Buttigieg and Klobuchar, a senator from Minnesota, lag in support among non-white voters, who are a core part of the Democratic electorate and typically a significant factor in primary battles.
Biden is counting on a robust showing next week in South Carolina, where he has enjoyed strong support among the state's sizable bloc of African-Americans, although Sanders has pulled even with him among black voters in some recent polls.