Fans and foes of Obamacare jockeyed for position outside the Supreme Court Wednesday. Inside, the justices weighed arguments in the case of King v. Burwell, which challenges a key part of the federal health law. Pete Marovich/UPI/Landov hide caption

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Supporters of the Affordable Care Act celebrate outside the Supreme Court in 2012, after a divided court upheld the law as constitutional by a 5-to-4 vote. The latest battle, which the Supreme Court hears Wednesday, is over whether people who buy insurance through federally run exchanges are eligible for subsidies. David Goldman/AP hide caption

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When lawyer Thomas Goldstein contended that innkeepers keep guest information anyway to stay in touch with their customers, Justice Scalia cut in: "Motel 6 does this? Jeez, I've never received anything from them!" iStockPhoto hide caption

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Arizona commission attorney Mary O'Grady (left) and Stephen Miller, a city council member, point to a possible redistricted map in 2011. Ross D. Franklin/AP hide caption

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Arizona state Sen. Andy Biggs flips through redistricting maps during a special legislative committee hearing to discuss the state commission's proposed maps in 2011. Ross D. Franklin/AP hide caption

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Want to get your teeth whitened? You may soon have more options. The U.S. Supreme Court ruled Wednesday that a state board of dentistry unfairly drove competitors out of business by trying to block non-dentists from providing whitening services. Vince Bucci/Getty Images hide caption

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U.S. Supreme Court police stand on the plaza in front of the courthouse in January. The court heard arguments Monday about whether an American had a right to know why their foreign-national spouse had been refused entry into the country. Jim Watson/AFP/Getty Images hide caption

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The Rev. Charles Perry of Unity Church, in Birmingham, Ala., marries Curtis Stephens, center, and his partner of 30 years, Pat Helms, Monday at the Jefferson County Courthouse. Alabama began issuing marriage licenses to same-sex couples Monday after the U.S. Supreme Court refused to block the marriages in the state. Hal Yeager/AP hide caption

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A demonstrator rallies outside the U.S. Chamber of Commerce against the Supreme Court's decision in favor of Citizens United five years ago. Eight protesters at the Supreme Court were arrested and charged. Nicholas Kamm/AFP/Getty Images hide caption

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