Sen. John Kerry, chairman of the Senate Foreign Relations Committee and President Obama's debate sparring partner, is now considered the leading candidate to replace Secretary of State Hillary Clinton, the beneficiary of United Nations Ambassador Susan Rice's fumbles on the recent Benghazi, Libya assassination.

Several sources told Secrets that Rice, while still a favorite of Obama and the West Wing, would face withering questions during a confirmation hearing and could be hit with congressional subpoenas even before Election Day as lawmakers determine if politics played a role in the muddled reports of what happened in Benghazi.

The sources also view Clinton's statement accepting full responsibility for the September 11 attack that killed four, including the U.S. ambassador to Libya, as a way to cover for Rice, who initially said the attack wasn't terrorism.

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Key House and Senate GOP leadership officials said that Rice would face tough questions, and other Republican sources said that efforts are underway to block her nomination and confirmation.

As a result, Kerry is rising to the top of the list of candidates. He has a long record in foreign policy, has acted as an able surrogate for the president, and commands deep respect in the Senate, meaning a quick confirmation.

A top GOP aide, asked about who would easily get through confirmation should Obama win a second term, said, "Kerry in a runaway. I can't think of anyone else close. Rice would have some trouble." Another aide to a Republican senator on the Foreign Relations Committee agreed that the Libya issue "will make it hard for her to get through."