WASHINGTON (CBSDC/AP) — President Barack Obama is defending U.N. Ambassador Susan Rice in the aftermath of the deadly Sept. 11 attack on a U.S. diplomatic post in Libya and calling Republican criticism of her outrageous.

At a White House news conference Wednesday, Obama pushed back against GOP senators who said they would do whatever is necessary to scuttle Rice’s nomination if the president picks her to replace Secretary of State Hillary Rodham Clinton.

The president said if Sen. John McCain wants to go after someone, he should challenge the president, not Rice.

“When they go after a U.N. Ambassador only because they think she’s an easy target,” Obama said, “then they’ve got a problem with me.”

McCain told reporters earlier Wednesday that he would do all he could to block a Rice nomination.

Sen. Lindsey Graham said he didn’t trust Rice.

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