Presidential candidate Bernie Sanders, I-Vt., walks offstage to greet the massive crowd gathered in New York's Washington Square Park on Wednesday. The Washington Post/The Washington Post/Getty Images hide caption

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Sen. Bernie Sanders speaks during a political rally on April 5 in Laramie, Wyo. Sanders spoke to a large crowd on the University of Wyoming campus after winning the Wisconsin primary. Theo Stroomer/Getty Images hide caption

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Bernie Sanders, I-Vt., pumps his fist during a campaign rally in Laramie, Wyo., Tuesday. Brennan Linsley/AP hide caption

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After Wisconsin, Demographics Suggest Rougher Terrain For Sanders, Cruz
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US Democratic presidential candidates Hillary Clinton (R) and Bernie Sanders smile after participating in the MSNBC Democratic Candidates Debate at the University of New Hampshire in Durham on February 4, 2016. Jewel Samad/AFP/Getty Images hide caption

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Has Bernie Sanders Pulled Hillary Clinton To The Left?
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Olin Dale Clayton waits for Bernie Sanders before a January event in Iowa with the United Steelworkers Local 310L. Sanders hopes his strength with white, working-class men can help him win in Ohio. Joe Raedle/Getty Images hide caption

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Bernie Sanders, pictured on Capitol Hill last June, has a steep hill to climb to win enough delegates in the presidential primary. But, he told NPR on Wednesday, "I am used to climbing steep hills." Lydia Thompson/NPR hide caption

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Bernie Sanders: 'Stay Tuned ... We Can Win This Thing'
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Bernie Sanders addresses a rally at Macomb Community College in Warren, Mich. Sanders needs a good showing in Michigan on Tuesday to start to turn his campaign around. Scott Olson/Getty Images hide caption

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Rabbi Daniel Rockoff of Orthodox Congregation Beth Israel Abraham Voliner estimates there about 250 Sabbath-observant families in Johnson County, Kan. Elle Moxley/KCUR hide caption

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When A Saturday Caucus Means No Voting For Orthodox Jews
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Walter Mondale, the 1984 Democratic presidential nominee, pumps his fist during his acceptance speech at the Democratic National Convention in San Francisco. Anonymous/AP hide caption

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Supporters of Democratic presidential candidate Sen. Bernie Sanders cheer and hold up signs, including one of Sanders, during a campaign rally at Colorado State University Sunday. Jacquelyn Martin/AP hide caption

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