As he pursues his uphill climb to defeat Hillary Clinton, Bernie Sanders appears to be making considerable progress in winning over key segments of the Democratic electorate that had been cool to his candidacy in the past, according to a POLITICO analysis of polling data.

In Wisconsin on Tuesday, one of his most consequential victories to date, the Vermont senator found a favorable electorate: Whites made up a higher percentage of the vote there than in all but four of the 20 states where entrance and exit polls have been conducted thus far.


He beat his previous performance — as measured by an aggregation of exit and entrance polls in 20 of the 32 states — among a wide array of demographic and ideological groups by at least 10 percentage points, including older voters and racial minorities who’ve been more resistant to his campaign.

Racial composition has been the most reliable predictor of Democratic primary outcome thus far. Clinton has won most of the more diverse states — with the exceptions of Sanders’ victories in Michigan and Hawaii. Sanders, on the other hand, has been the victor in most of the overwhelmingly white states, save for Iowa and Massachusetts, which Clinton won narrowly.

But in Wisconsin, Sanders both expanded his advantage with white voters — from 49 percent to 59 percent — and made inroads with African-Americans. Among black voters, Sanders won 31 percent, better than his average of 19 percent — and a tick above the 28 percent he won in his narrow Michigan upset.

By age, Sanders captured 82 percent of voters younger than 30, well above the 71 percent he had captured to this point. He even surpassed his performance among voters 65 and older: 37 percent in Wisconsin, compared with 26 percent in all the states combined.

But the insurgent Vermont senator — an independent seeking the Democratic presidential nomination — must continue to beat many of those benchmarks in the upcoming states, especially in racially diverse states that don’t allow independents to vote in primaries, in order to threaten Clinton seriously for the nomination.

In their next primary — New York on April 19 — only registered Democrats, who have favored Clinton thus far, will be allowed to participate. And minorities will make up about 3-in-10 Democratic primary voters, more than the 17 percent in Wisconsin.

Even if Sanders does surpass Clinton in New York and subsequent states, it’s still very unlikely he can accrue enough delegates to overtake Clinton — let alone win a majority among the pledged delegates to counter Clinton’s current edge with unpledged superdelegates.

But Sanders undoubtedly has momentum. He trails Clinton by only 6.6 percentage points in the latest HuffPost Pollster average, down from more than 14 points immediately before the Iowa caucuses.

Some of the states coming later this month represent a demographic challenge for the senator. Only about two-thirds of Democratic voters in New York on April 19 are expected to be white. The April 26 primaries are more of a mixed bag: Whites were just 53 percent of the primary electorate in Maryland back in 2008, but made up more than 80 percent in Connecticut and Pennsylvania.

The gender gap was another place where Sanders showed progress in Wisconsin: For the first time in an exit poll state since the New Hampshire primary on Feb. 9, Sanders won the female vote in the Badger State, 50 percent to 49 percent. He has won only 37 percent of the female vote so far in the primaries overall.

Sanders won easily among men in Wisconsin, 64 percent to 35 percent. He has won 48 percent of the male vote up until now.

Young voters continue to go for Sanders by wide margins, but Sanders grew his appeal across the board in Wisconsin. His performance among voters younger than 30 was 11 points better than his average. But he also jumped 18 points among voters aged 30-44, capturing 66 percent of the vote. (He was up 12 points among voters 45-64, and 11 points among seniors.)

It’s not just demographics: Sanders also won Democratic primary voters across ideological lines on Tuesday night, beating his past performance. He won voters who identified as “very liberal,” 62 percent to 38 percent — better than the roughly half of “very liberal” voters he’s won thus far.

He also won 58 percent of “somewhat liberal” and 51 percent of “moderate” voters — improvements of 15 points among each group.

In addition, Sanders made significant progress among self-identified Democrats in Wisconsin — which could reduce his reliance on independent voters, who are barred from participating in many of the upcoming Democratic primaries. The independent senator won half of Democrats in Wisconsin — far better than the 35 percent he’s taken across the 21 states surveyed.

Independents, on the other hand, have always been a Sanders stronghold. He’s won 62 percent of voters who identify as independents thus far, and he got 72 percent of the independent vote in Wisconsin on Tuesday.

But in the other states conducting primaries this month, only Rhode Island allows independents to participate in the Democratic primary. Primaries in New York, Connecticut, Delaware, Maryland and Pennsylvania will be closed to independents.

While some voters still identify in the exit poll as independents in these closed primary states, there are fewer than in open states — since all the voters in closed states are still registered Democrats.

In New York, for example, 87 percent of 2008 primary voters identified as Democrats in the exit poll — significantly more than the 71 percent in Wisconsin’s open primary on Tuesday. In Pennsylvania, Democrats made up 82 percent of the 2008 closed primary electorate.

That’s a challenge for Sanders, who tied Clinton among self-identified Democrats on Tuesday and has only defeated her among them in one of the exit-poll states: New Hampshire, where Sanders won, 52 percent to 48 percent. (Sanders has won closed caucuses in Colorado, Kansas, Maine and Nebraska.)

(One note on methodology: Sanders won 10 of the 12 states where there were no entrance or exit polls, so the aggregated exit poll results could underestimate him to some degree. The 10 states Sanders won were caucus states — which generally attract fewer voters — some by yawning margins. Clinton won the two primary states without exit polls: Arizona and Louisiana.)