Attorney William Johnson, a leader of the American Freedom Party and self-proclaimed white nationalist, made it onto Trump's list of delegates. He now says he will not attend the convention. Jae C. Hong/AP hide caption

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Donald Trump and his wife, Melania, arrive to speak to supporters at Trump Tower in New York following his victory in Indiana Tuesday. Improbably, Trump is now assured of being the GOP nominee. Spencer Platt/Getty Images hide caption

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Donald Trump, the front-runner for the Republican presidential nomination, gave an outline of his worldview and foreign policy goals in an address in Washington Wednesday. Evan Vucci/AP hide caption

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Sen. Bernie Sanders waves to a crowd gathered at Gettysburg College in Gettysburg, Pa., on Friday. Pennsylvania holds its presidential primary Tuesday. Mark Wilson/Getty Images hide caption

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Sanders Adviser Says Campaign May Have To 'Re-Evaluate' After Tuesday
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Presidential candidate George Wallace reaches out for the hands of his supporters at the Texas State Convention of his American Independent Party, Dallas, Sept. 17, 1968. PhotoQuest/Getty Images hide caption

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Is Donald Trump A Modern-Day George Wallace?
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In a Republican race marked by anger and anti-establishment fervor, Kasich is running the optimistic campaign. Is that enough to win? Andrew Burton/Getty Images hide caption

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Balloons fall at the 2012 Republican National Convention in Tampa, Fla. This year's convention in Cleveland is likely to be far more complicated. Charles Dharapak/AP hide caption

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Can A Candidate Pay Delegates? Plus, 3 Possible GOP Convention Scenarios
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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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