President Obama speaks at the National Defense University in Washington, D.C., on May 23. Win McNamee/Getty Images hide caption

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President Obama speaks about the Affordable Care Act at the White House on May 10. Mandel Ngan/AFP/Getty Images hide caption

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President Obama speaks at Ellicott Dredges in Baltimore on May 17. The trip followed a visit by the company's president to Capitol Hill to testify in support of the Keystone XL pipeline. The White House says Obama's speech had nothing to do with Keystone, but environmental groups have been frustrated with his stance on the issue. Mandel Ngan/AFP/Getty Images hide caption

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Richard Nixon says goodbye to members of his staff outside the White House as he boards a helicopter after resigning the presidency on Aug. 9, 1974. AP hide caption

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President Obama's commencement speeches seem to be his real State of the Union addresses. On May 5, he told Ohio State students that they were graduating into a "healing" economy. Carolyn Kaster/AP hide caption

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President Obama speaks during a news conference in the White House Rose Garden on Thursday. He told reporters: "Leaks related to national security can put people at risk." Mark Wilson/Getty Images hide caption

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Last week, FBI investigators and a Watertown, Mass., police officer investigate the scene near the boat where bombing suspect Dzhokhar Tsarnaev was hiding. Democrats have argued that the way the government responded to the Boston attacks makes a case for not cutting too deeply. Kevork Djansezian/Getty Images hide caption

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President Obama makes a statement in the White House briefing room just a few hours after the bombings at the Boston Marathon on April 15. Win McNamee/Getty Images hide caption

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