Libby, who had been Cheney's chief of staff and close adviser, was convicted of perjury and obstruction of justice for his role in the leaking the name of CIA operative Valerie Plame to the public.
Cheney "went to the mat and came back and back and back at Bush," one source told the Daily News. "He was still trying the day before Obama was sworn in."
Another said Cheney was "furious with Bush" for opting not to pardon Libby. Had the president done so, he would likely have faced outrage for exonerating the most prominent figure to be punished in the Plame affair.
As the Daily News notes, Cheney expressed his frustration over the matter in a Weekly Standard interview just one day after he abdicated the vice presidency.
Libby "was the victim of a serious miscarriage of justice, and I strongly believe that he deserved a presidential pardon," said Cheney. "Obviously, I disagree with President Bush's decision."