Senate Panel Questions Nominee for U.N. Ambassador WASHINGTON - Samantha Power received a mostly cordial reception on Wednesday from senators weighing her nomination as the next United States ambassador to the United Nations, though Republicans pressed her to explain past comments on Israel and Palestine and certain "crimes" she once said had been committed by the United States. Ms. Power, 42, a former journalist and national security specialist who has written extensively about genocide and humanitarian intervention, appeared to face no serious obstacles to confirmation during the hearing by the Foreign Relations Committee. She offered no clear map for how she might press the Obama administration for a more forceful response to the violence in Syria. If confirmed by the committee and then the full Senate, Ms. Power would succeed Susan E. Rice, whom Mr. Obama has named as his new national security adviser. Several key Republican senators, including Bob Corker of Tennessee, the ranking member of the committee, and John McCain of Arizona, offered their support. "I know you're going to be received very well," Mr. Corker said at the outset of the hearing. Her path forward was undoubtedly eased by an earlier endorsement from Mr. McCain, as well as an unusual statement from the Israeli ambassador to Washington, Michael B. Oren, who departed from normal protocol of not commenting on such a presidential nomination in order to make clear that Israel had no qualms about her. Still, she faced some difficult questions from Republicans, perhaps most notably Senator Marco Rubio of Florida, over controversial remarks and positions she has taken in the past. His first question was about a 2002 interview in which she suggested that the United States might have to spend billions of dollars to support a "mammoth protection force" and "a meaningful military presence" if Palestinian statehood were ever to be realized. As she has before, Ms. Power distanced herself from the remarks. "I gave a long, rambling and remarkably incoherent response to a hypothetical question that I should never have answered," she said. She added: "Peace can only come about through a negotiated solution. There is no shortcut. Ms. Power vowed to fight within the United Nations against what she called "unacceptable bias and attacks against the state of Israel." She went further, saying she would "absolutely" press for Israel to be given its first rotating seat on the United Nations Security Council. Ms. Power also appeared uneasy, if unsurprised, when Mr. Rubio asked her about a 2003 article on foreign policy in which she argued for "a historical reckoning with crimes committed, sponsored, or permitted by the United States." In the article in New Republic magazine, she wrote: "A country has to look back before it can move forward. Instituting a doctrine of the mea culpa would enhance our credibility by showing that American decision makers do not endorse the sins of their predecessors. Although Mr. Rubio pressed her to say what those "crimes" or "sins" were, Ms. Power repeatedly sidestepped. "I, as an immigrant to this country, think this country is the greatest country on earth," said Ms. Power, whose parents immigrated from Ireland when she was 9. I would never apologize for America - America is the light to the world. Several Republicans, even those clearly supporting her, gave her items on their wish lists. Mr. McCain urged her to press within the United Nations for more decisive action against the Syrian government in the face of the killings of tens of thousands of its opponents. But Rand Paul, the libertarian-minded senator from Kentucky, said that while he believed she had "noble purposes," she should remember that even when a military action has a humanitarian objective, "people do lose their lives." Ms. Power was candid in acknowledging, a bit ruefully, that the candor of her past comments, made without the constraints of government office, had in some ways come back to haunt her. "Serving in the executive branch," she said she had come to realize, "is very different from sounding off from an academic perch." Ms. Power spent several years at the Harvard University Kennedy School of Government. Senator Tim Kaine, Democrat of Virginia, helped her navigate that remark toward a soft landing, saying, "I don't think blunt and outspoken is usually a great qualification for a diplomatic post. But for this one, it is.