O'Malley goes from endorsing Clinton to challenging her

O'Malley flashback: The 2007 Clinton endorsement
O'Malley flashback: The 2007 Clinton endorsement

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O'Malley flashback: The 2007 Clinton endorsement 01:15

Washington (CNN)Martin O'Malley was an early and vocal supporter of Hillary Clinton's 2008 presidential campaign. Fast-forward eight years, and the former Maryland governor is taking on the former secretary of state for the same job.

But back then, O'Malley proudly proclaimed Clinton as the best candidate for the presidency.
"Senator Clinton has spent her entire life being a champion for the working families whose hopes and whose dreams are the very core of our nation," O'Malley said on May 9, 2007, standing aside Clinton in front of the Annapolis, Maryland waterfront. "Today, it is with great pride and enthusiasm that I endorse my friend, Senator Hillary Rodham Clinton, to be the next president of the United States."
"Thank you, my friend, that was great," Clinton said in an off-mic moment.
    On Friday, ahead of O'Malley's expected presidential announcement in Baltimore on Saturday, the governor's spokeswoman simply said that was then, this is now.
    "Governor O'Malley has tremendous respect for Secretary Clinton, but times change," said Haley Morris. "We need new leadership to address our nation's big challenges right now -- from the continued law breaking on Wall Street to a broken economy that's leaving too many Americans behind. Governor O'Malley has the progressive values and record of getting things done to take these challenges on."
    O'Malley strikes contrast with Clinton on justice reform
    O'Malley strikes contrast with Clinton on justice reform

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      O'Malley strikes contrast with Clinton on justice reform

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    O'Malley strikes contrast with Clinton on justice reform 06:08
    O'Malley has been close to the Clintons since he was the mayor of Baltimore in the early 2000s. Bill and Hillary Clinton have raised money for O'Malley throughout his career and tapped their network to help him. O'Malley served as the chair of Clinton's 2008 campaign in Maryland.
    When O'Malley endorsed Clinton in 2007, Clinton said, "Martin is a terrific leader whose innovative initiatives have been emulated around the country."
    Despite that history, the two will now face off for the presidency. On Friday, O'Malley called Clinton to inform her of his plans to run for president, a source with knowledge of the call told CNN. The conversation was short and cordial, the source said.
    On Saturday, a tweet from Clinton's official Twitter account -- signed with "H" to indicate it was penned by the candidate herself -- welcomed O'Malley's candidacy.
    O'Malley is behind Clinton in every poll, but his aides have confidently written off national polling.
    The former governor has largely been careful when attacking Clinton, but at times has bluntly knocked her.
    "Let's be honest here," O'Malley said on ABC in March. "The presidency of the United States is not some crown to be passed between two families."