The survey was conducted partly in the days after Sanders captured victory Tuesday in the New Hampshire primary, having previously won the popular vote in the Iowa caucuses last week. Buttigieg achieved the most state delegate equivalents in that first-in-the-nation contest.

Nevada's upcoming caucuses, set to take place Feb. 22, will represent the Democratic candidates’ first true test among the Latino community and other voters of color. The White House contenders must then demonstrate strength in South Carolina’s primary on Feb. 29 among the state's majority-black Democratic electorate.

Those two successive contests will likely determine the fate of Biden’s faltering campaign, which is counting on impressive performances in both states and contending with ascendant moderates Buttigieg and Klobuchar — who placed second and third in New Hampshire, respectively.

Then comes Super Tuesday on March 3, when more than a dozen states will hold their primaries and former New York Mayor Mike Bloomberg will begin competing for delegates. The next televised debate among the candidates is scheduled Feb. 19 in Las Vegas.

The Nevada Poll contacted 413 likely caucusgoers by phone from Tuesday through Thursday. The margin of error is 4.8 percentage points.