Bernie Sanders' victory in Indiana brings his winning total to 17 state contests.

How? Well, he partially answers the questions himself. Indiana exit polling shows that he won, among other groups, the vote of people 45 years of age or younger. Almost half of the Indiana Democratic voters were younger than 45 and among them, about two-thirds support Sanders.

Sanders had strong support from liberals and independents, as well as the support of both men and women. He led among men by a larger margin, however, getting the support of 57 percent of males. Hillary Clinton and Sanders basically split women's votes.

Clinton continues to perform well among African American voters. But in Indiana, they make up just 17 percent of Democratic primary voters. Three-quarters supported Clinton, while Sanders won (58 percent) among the three-quarters of white Democratic Indiana primary voters.

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Sanders' criticism of Clinton's Wall Street ties may have made a difference to Indiana Democratic voters. Among the majority (64 percent) who said Wall Street hurts the economy, the majority (62 percent) supported Sanders.

As has been the trend throughout much of this campaign, more Indiana Democratic primary voters said Sanders (84 percent) is honest and trustworthy than about Clinton (55 percent). On the other hand, more voters perceive Clinton's policies (76 percent) to be realistic than Sanders' policies (63 percent).

There is also general optimism around both candidates heading into November. Whereas Republican voters felt divided by this process, the same does not seem to be true of the Democratic side. Majorities of both Clinton voters and Sanders voters say the Democratic campaign has mostly energized the Democratic Party.

Most Democratic voters would be excited or optimistic if either Clinton or Sanders were to be elected president. The majority of Indiana Democratic primary voters are more inspired about the future of the country by Sanders (56 percent) as opposed to Clinton (42 percent). If Sanders were elected president, many more voters would be optimistic/excited (72 percent) than concerned/scared (26 percent). Clinton also garners a similar level of optimism/excitement (68 percent). So both candidates have positive support and that support does not totally dissipate when discussing the other candidate.

When discussing the November elections, the majority of both Clinton and Sanders supporters would back the other. About a third of Sanders' primary voters currently say they would not back Clinton in November, and only 22 percent of Clinton supporters say they wouldn't vote for Sanders. More Indiana Democratic primary voters think Clinton (54 percent) would have a better chance to defeat Trump than Sanders (43 percent).

To date, this is the highest percentage that thought Sanders could beat Trump.

Melissa Herrmann is president of SSRS, a market and survey research firm based in Pennsylvania.