LAS VEGAS — Nevada kicks off a new phase of the Democratic presidential race Saturday as the first 2020 contest with an electorate that reflects the diversity of the party.

It could be a knockout round for candidates who fail to attract a broad coalition of voters. Whether or not it causes some of them to exit, Nevada will signify to voters in critical upcoming contests who is viable and who isn’t.

Polls say Sen. Bernie Sanders, I-Vt., is the front-runner heading into the caucuses, with former Vice President Joe Biden, former South Bend, Indiana, Mayor Pete Buttigieg, Sen. Elizabeth Warren, D-Mass., businessman and philanthropist Tom Steyer and Sen. Amy Klobuchar, D-Minn., all in the hunt. Former New York City Mayor Mike Bloomberg, who is surging in national surveys and had a rocky debate this week, is skipping the first four states and won't be on the ballot here.

Here are five things to watch for as Nevada Democrats vote.

More Iowa-style mayhem?

Nevada’s contest is a caucus like Iowa, featuring new technologies that have added uncertainty to an already complex voting system. Some experts fear problems reminiscent of the mayhem of Iowa's first-in-the-nation contest, where a poorly designed app helped cause a breakdown in reporting processes that led to extensive delays and confusion about who won that race.

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High turnout during an early voting period in Nevada indicates that officials in charge are likely to have their hands full on caucus day. State party officials have expressed confidence in the process, but Democratic National Committee Chair Tom Perez sought to lower expectations by stopping short of promising results on the day of the caucuses. He told The Associated Press the top goal was “accuracy” rather than speed of reporting. Will the trains run on time, or will it be another night of chaos with no clear winner?

Who will win Latinos and black voters?

Nevada's Democratic caucus electorate in 2016 was 59 percent white, 19 percent Latino and 13 percent black, according to entrance polls. After predominantly white Iowa and New Hampshire, this state is the first meaningful test of each candidates' strength with the latter constituencies. Latinos form a large part of the electorates in delegate-rich states such as California and Texas, which vote March 3. Black voters have propelled every Democratic nominee to the prize since 1992. Keep an eye on who performs well — and poorly — with these groups. It'll shape the fate of their campaigns.

Where is Bernie Sanders vulnerable?

Sanders is looking like an increasingly formidable front-runner after a popular vote win in Iowa and a clear victory in New Hampshire propelled him to the lead in primary polls nationally and in important upcoming states such as Texas, California and North Carolina. At the NBC News and MSNBC debate Wednesday, rivals threw everything they had at him, knocking him for a lack of transparency on health records, the high cost of his health care plan and his more-than-a-decade-old votes against gun control and liberalizing the immigration system. Many have since kept up the attacks on the campaign trail.

Has any of it hurt him? Are Latinos breaking away? Will his young base turn out? Could older Democrats turned off by his democratic socialism look to send a message? The caucuses will offer a clue as to what, if any, vulnerabilities rivals can exploit to try and knock the front-runner off his perch.

Will Elizabeth Warren's debate tour de force help her?

Warren's fiery debate performance led to a windfall of campaign contributions and widespread praise from pundits after she landed blow after blow on Bloomberg and laced into rivals Buttigieg, Biden and Klobuchar. She desperately needs a jolt of electricity after disappointing third and fourth-place finishes in Iowa and New Hampshire that narrowed her path to the nomination. Nevada could mark the beginning of a Warren comeback, or the beginning of the end. Her opportunities are dwindling, with upcoming states even more demographically challenging for her than the first three, with larger shares of the black voters she's struggled to win over.

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Will anybody drop out?

The Democratic establishment is increasingly fretting that a traffic jam in the "moderate lane" is clearing the way for Sanders to consolidate the left and cruise to the nomination. Biden, Bloomberg, Buttigieg and Klobuchar are all competing for middle-of-the-road voters, and moderate Democrats believe the best chance they have to stop Sanders is for most of those contenders to drop out and rally voters around one clear option. It won’t be easy to persuade Buttigieg, Biden or Bloomberg to step down — they’re private citizens with no political office to return to if they drop out.

There wasn’t much winnowing among major candidates after Iowa or New Hampshire. Will that change in Nevada? One week after this comes South Carolina, just three days before the cluster of Super Tuesday contests that award one-third of delegates. If Democrats don’t rally around an alternative by then, Sanders could pull ahead with an insurmountable lead.