(CNN) Vermont Sen. Bernie Sanders is the prohibitive frontrunner for the 2020 Democratic presidential nomination. It's not just that he had more people cast a ballot for him in each of the first three contests. It's how Sanders is doing it compared to his last run in 2016.

Sanders is putting together a multiracial coalition, adding nonwhite voters to his white non-college base.

Four years ago, Sanders' base of support was white voters . In fact, he basically fought Hillary Clinton to a draw among white voters. The reason he lost was because Clinton beat him among black and Hispanic voters, who make up more than one-third of the Democratic Party in total.

This year, Sanders is doing about the same or even better among nonwhite voters than he is among white voters. In Nevada , he won 29% of white voters. Compared to 2016, he did 22 points better among Hispanic voters there by earning 51% of their support. Even among black voters who he lost by over 50 points to Clinton, Sanders picked up 27% support.

The uptick in support with both groups is worth noting. Hispanic voters are, by themselves, about 15% of the voters in a Democratic primary. They make up huge chunks of voters in the delegate rich Super Tuesday states of California and Texas . It's not surprising that he has taken the lead in both states with an especially clear advantage in California.

Sanders' support among black voters is stunning when you compare it to 2016. Sanders came in with 22% of the vote among black voters in the 2016 Nevada caucuses . That means he increased his vote share among black voters by 5 points in 2020, even as his overall share of the vote dropped dramatically in a field with a lot of candidates.

And while Iowa and New Hampshire don't have as large of a Hispanic or black populations, we saw the same patterns developing there. Sanders won 43% of and 36% of the nonwhite vote in Iowa and New Hampshire respectively. This compares with 21% and 25% of the white vote in Iowa and New Hampshire respectively.

Sanders' growing black support may allow him to beat former Vice President Joe Biden in South Carolina on Saturday. In 2016, Sanders lost the state by nearly 50 points to Clinton. Clinton went on to win the lionshare of delegates from the Southern states. This year, it looks likely at this point that we'll be seeing a far different delegate picture emerge from the South.

But it's not just that Sanders is doing better among nonwhites. He's also holding onto white voters without a college degree.

As I noted at the beginning of this cycle, white voters without a college degree make up about a quarter of the electorate . They were part of what I called "the hidden Democratic Party." That is, they are a substantial part of the party, even though the media is often more likely to pay attention to whites with a college degree.

Sanders actually did well among whites without a college degree in 2016. He beat Clinton by about 7 points in the states that had an entrance or exit poll. He lost by about that same margin among whites with a college degree.

Sanders won among whites without a college degree in the first three contests. In Nevada, he took 35% of the non-college white vote. His closest competitor was former South Bend, Indiana, Mayor Pete Buttigieg at 18%. Among whites with a college degree, Sanders only got 24% of the vote. Buttigieg was just behind at 20%.

The same held true in Iowa and New Hampshire. Sanders took 29% among whites without a college degree in Iowa, while earning just half that, 15%, among white with a college degree. In New Hampshire, the split was 30% among whites without a college degree and 21% among whites with one.

It's difficult to find any state on the primary map that doesn't have either a substantial proportion of nonwhites or whites without a college degree. This is key because it means Sanders is likely to do well all over the map. He should be able to hit the 15% threshold needed to win delegates in almost every state and congressional district.

Sanders' coalition is unique compared to Clinton or Barack Obama. Both of them won nonwhites but teamed them with whites with a college degree.

You really have to go back to Bill Clinton in 1992 to find the last Democrat to win a competitive primary with the support of non-college whites and nonwhites.

We'll see whether Sanders will ultimately be as successful as he was.