• Billionaire Tom Steyer's poll surge helped him qualify for next debate
  • Entrepreneur Andrew Yang failed to meet polling thresholds and won't qualify
  • The Democratic debate will be held in Des Moines, Iowa, on Feb. 3

The next Democratic primary, set for Jan. 14, already has six qualifying candidates but has had to drop Andrew Yang for failing to meet certain polling and fundraising requirements.

The debate field will include former Vice President Joe Biden, former South Bend Mayor Pete Buttigieg, Sen. Amy Klobuchar (D-Minn.), Sen. Bernie Sanders (I-Vt.), Sen. Elizabeth Warren (D-Mass.) and billionaire Tom Steyer, ABC News' FiveThirtyEight reported.

With Yang being dropped this time around, the fact that now only white candidates will appear on the debate stage might well cause criticism of the Democrats’ lack of diversity to grow louder.

It’s also worth noting that Steyer’s inclusion was somewhat surprising, given not only his late entry into the primary race but his previous polling which hadn’t placed him among the front runners. However, recent surging in the polls has begun to turn things around. The billionaire and philanthropist from California is, in many ways, pitching himself as running the Democratic version of Trump’s populist campaign, using a left-wing approach. Steyer’s platform includes a wealth tax, decriminalized border crossings and prioritizing action on climate change.

Steyer also plans to spend at least $100 million of his own money to fund his campaign, angling himself as a Washington outsider.

To qualify, candidates had to have had at least 225,000 unique donors as well as get at least 7 percent in two early-state polls or 5 percent in four or more national polls between Nov. 14 and Jan. 10.

Although former New York City Mayor Michael Bloomberg met the polling threshold, because he does not solicit campaign donations, he did not qualify. Yang and Sen. Cory Booker (D-N.Y.) both met the donor threshold, but neither made the cut in the polls.

This coming debate may prove the most important one of the Democratic primary. Being held in Des Moines, Iowa, less than three weeks before the state becomes the first to vote. This is very significant as Iowa is a very important state to win because its eventual choice has the ability to affect other states’ choices.

In the latest polling averages, per RealClearPolitics, Sanders and Buttigieg are tied at roughly 22 percent, with Biden close behind at 20.3 percent. It’s an extremely close contest that could easily favor any of the top candidates come Feb. 3 in Iowa.

Tom Steyer Anti-Trump Billionaire Tom Steyer hosts a town hall meeting on December 4, 2018 in Charleston, South Carolina. Photo: Sean Rayford/Getty Images