Hillary Clinton speaks at an event in New Hampshire earlier this month. The presidential candidate continues to face questions over her emails as secretary of state. Darren McCollester/Getty Images hide caption

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In his congressional office, Rep. Bob Brady, D-Pa., drinks from the glass of water Pope Francis used during his speech to Congress. Stan White/U.S. Rep. Bob Brady's office via AP hide caption

itoggle caption Stan White/U.S. Rep. Bob Brady's office via AP

Hillary Clinton asks protesters opposed to the Keystone XL oil pipeline to stop disrupting her campaign event Friday in Portland, Maine. Robert F. Bukaty/AP hide caption

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Supporters of Democratic presidential candidate Hillary Clinton cheer as she arrives at the state's annual Democratic convention Saturday in Manchester, N.H. Jim Cole/AP hide caption

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Benjamin Purdy, 20, wants the next president to focus on prison reform. He says jailing non-violent drug offenders is "sucking so much money out of our budget." Asma Khalid/NPR hide caption

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Asking Tonight Show host Jimmy Fallon if he had ever touched Donald Trump's "real hair," (he had not) Clinton offered "you want to touch mine?" Douglas Gorenstein/NBC via AP hide caption

itoggle caption Douglas Gorenstein/NBC via AP

Democratic presidential candidate Bernie Sanders was tweeting up a storm during Wednesday night's Republican debate. Win McNamee/Getty Images hide caption

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People can now contribute to presidential campaigns with just a few taps on a smartphone. Jonathan Alcorn/AFP/Getty Images hide caption

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Hillary Clinton waits behind a curtain before a rally at the University of Wisconsin, Milwaukee on Thursday. She continues to struggle to explain her use of a private email server while secretary of state. Morry Gash/AP hide caption

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Demonstrators march in the snow outside the White House during a rally against the Supreme Court's decision five years ago in favor of Citizens United, which allows private citizens and corporations to make unlimited donations for political campaigns. Nicholas Kamm/AFP/Getty Images hide caption

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A man carries a cardboard cutout of Hillary Clinton in Des Moines, Iowa. Clinton and other traditional candidates have struggled to breakthrough as outsiders have captured the attention this summer. Charlie Neibergall/AP hide caption

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