Former Florida Gov. Jeb Bush has said his decision to run for the Republican nomination will be based on two things: his family and whether he can lift America's spirit. His father and brother are former Presidents.
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Wisconsin Gov. Scott Walker has created a political committee that will help him travel and raise money while he considers a 2016 bid. Additionally, billionaire businessman David Koch said in a private gathering in Manhattan this month that he wants Walker to be the next president, but he doesn't plan to back anyone in the primaries.
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Louisiana Gov. Bobby Jindal is establishing a committee to formally explore a White House bid. "If I run, my candidacy will be based on the idea that the American people are ready to try a dramatically different direction," he said in a news release provided to CNN on Monday, May 18.
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Sen. Bernie Sanders, an independent from Vermont who caucuses with Democrats, has said the United States needs a "political revolution" of working-class Americans looking to take back control of the government from billionaires. He first announced the run in an email to supporters early on the morning of Thursday, April 30.
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On March 2, retired neurosurgeon Ben Carson announced the launch of an exploratory committee. The move will allow him to raise money that could eventually be transferred to an official presidential campaign and indicates he is on track with stated plans to formally announce a bid in May.
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South Carolina Sen. Lindsey Graham has said he'll make a decision about a presidential run sometime soon. A potential bid could focus on Graham's foreign policy stance.
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Hillary Clinton launched her presidential bid Sunday, April 12, through a video message on social media. She continues to be considered the overwhelming front-runner among possible 2016 Democratic presidential candidates.
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Sen. Marco Rubio announced his bid for the 2016 presidency on Monday, April 13, a day after Hillary Clinton, with a rally in Florida. He's a Republican rising star from Florida who swept into office in 2010 on the back of tea party fervor. But his support of comprehensive immigration reform, which passed the Senate but has stalled in the House, has led some in his party to sour on his prospects.
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Lincoln Chafee, a Republican-turned-independent-turned-Democrat former governor and senator of Rhode Island, said he's running for president on Thursday, April 16, as a Democrat, but his spokeswoman said the campaign is still in the presidential exploratory committee stages.
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Jim Webb, the former Democratic senator from Virginia, is entertaining a 2016 presidential run. In January, he told NPR that his party has not focused on white, working-class voters in past elections.
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Vice President Joe Biden has twice before made unsuccessful bids for the Oval Office -- in 1988 and 2008. A former senator known for his foreign policy and national security expertise, Biden made the rounds on the morning shows recently and said he thinks he'd "make a good President."
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New Jersey Gov. Chris Christie has started a series of town halls in New Hampshire to test the presidential waters, becoming more comfortable talking about national issues and staking out positions on hot topic debates.
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Rep. Paul Ryan, a former 2012 vice presidential candidate and fiscally conservative budget hawk, says he's keeping his "options open" for a possible presidential run but is not focused on it.
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Sen. Rand Paul officially announced his presidential bid on Tuesday, April 7, at a rally in Louisville, Kentucky. The tea party favorite probably will have to address previous controversies that include comments on civil rights, a plagiarism allegation and his assertion that the top NSA official lied to Congress about surveillance.
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Texas Sen. Ted Cruz announced his 2016 presidential bid on Monday, March 23, in a speech at Liberty University. The first-term Republican and tea party darling is considered a gifted orator and smart politician. He is best known in the Senate for his marathon filibuster over defunding Obamacare.
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Democrat Martin O'Malley, the former Maryland governor, released a "buzzy" political video in November 2013 in tandem with visits to New Hampshire. He also headlined a Democratic Party event in South Carolina, which holds the first Southern primary.
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Republican Rick Perry, the former Texas governor, announced in 2013 that he would not be seeking re-election, leading to speculation that he might mount a second White House bid.
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Former Pennsylvania Sen. Rick Santorum, a social conservative, gave Mitt Romney his toughest challenge in the nomination fight last time out and has made trips recently to early voting states, including Iowa and South Carolina.
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Political observers expect New York Gov. Andrew Cuomo to yield to Hillary Clinton's run in 2016, fearing there wouldn't be room in the race for two Democrats from the Empire State.