What GOP senators could do to block Rice If President Barack Obama selects United Nations envoy Susan Rice to replace Secretary of State Hillary Clinton, he'll face determined opposition from at least three Republican senators: John McCain of Arizona, Lindsey Graham of South Carolina and Kelly Ayotte of New Hampshire. Ayotte and Graham would each place a "hold" on Rice's nomination if she were nominated, their aides told NBC News Tuesday. McCain's office did not immediately respond to a request for comment. The three GOP senators met with Rice Tuesday and said afterwards they still weren't satisfied with the administration's handling of the aftermath of the Sept. 11 attack on the US consulate in Benghazi and Rice's initial role in explaining that attack. Related: Senators not satisfied with Rice's Benghazi story If Rice were nominated and her nomination came to the Senate floor for a vote, it seems highly likely that with Democrats holding the majority in the new Congress, she'd be confirmed. But her Republican opponents could use the Senate rules to try to prevent her nomination from coming to a floor vote. A "hold" is an informal procedure by which a senator signals to his or her floor leader that he or she doesn't want a bill or nomination to come to the floor. Holds have been used for years by senators to indicate that a nomination is so unacceptable to them that they'd try to filibuster it -- to stop it through endless debate -- if necessary. Ambassador Nicholas Burns talks about Ambassador Susan Rice's meeting with Sens. John McCain, Kelly Ayotte and Lindsey Graham. He also talks about the challenges facing the next Secretary of State. "I would hold her nomination until I had additional answers to questions, and then I will render judgment," Ayotte told reporters after meeting with Rice. When Graham was asked by Defense News if he would place a hold on Rice's nomination, he said, "Oh, absolutely. I would place a hold on anybody who wanted to be promoted to any job who had a role in the Benghazi situation. Graham's office confirmed that account. Graham told a press conference Tuesday after he, McCain and Ayotte met with Rice that "before anybody can make an intelligent decision about promoting someone involved in Benghazi, we need to do a lot more (investigating)." But indicating they'd put a hold on a nomination does not mean that Rice's opponents could themselves kill her nomination. If Rice were nominated and if the Foreign Relations Committee reported her nomination to the full Senate, it would be up to Majority Leader Harry Reid to decide when to bring it to the floor for debate. Sen. John McCain, R-Ariz., ranking Republican on the Senate Armed Services Committee, center, flanked by fellow committee members, Sen. Kelly Ayotte, R-N.H., left, and Sen. Lindsey Graham, R-S.C., right, speaks on Capitol Hill in Washington, Tuesday, Nov. 27, 2012, following a meeting with UN Ambassador Susan Rice. Rice met with lawmakers to discuss statements she made about the attack on the U.S. Consulate in Libya that left the ambassador and three other Americans dead. If senators opposed to Rice were able to keep debating the nomination, and if Reid failed to muster 60 votes for cloture, bringing the debate to a close, then the nomination would essentially be dead. It's early in this battle, and it's not clear there would be enough Republicans to sign onto a filibuster, but one Democratic Senate aide said Democrats would welcome the fight and are confident she would be confirmed. "People are happy to fight for her," the aide said. There are echoes here of the nomination battles of the Bush era. Democratic filibusters blocked, and ultimately killed, a number of President George W. Bush's judicial nominees and Bush's nomination of John Bolton to be U.N. ambassador. "I remember the John Bolton episode pretty well," Graham told reporters Tuesday. Democrats dug in their heels saying we're not gonna vote, we're not gonna consider this nomination until we get basic answers to our concerns. There were two cloture votes on Bolton's nomination in 2005. He got 56 votes on one of them, four shy of the number needed to end debate and confirm him. In some cases, a senator putting a hold on a nomination is enough to convince the majority leader or the chairman of the committee considering the nomination to not try to move ahead with it. For example in December 2011 the Washington Post reported that Matthew Bryza, Obama's nominee to be ambassador to Azerbaijan, was "deemed insufficiently hostile to Armenia's enemies by the Armenian National Committee of America (ANCA) and two Democratic senators with Armenian American constituencies, Barbara Boxer (Calif.) and Robert Menendez (N.J.)." Boxer and Menendez put a hold on his nomination, preventing or at least delaying a floor vote. Obama gave Bryza a recess appointment and renominated him. But Boxer and Menendez continued to oppose him and the Post reported that Foreign Relations Committee Chairman Sen. John F. Kerry, D-Mass., never scheduled a hearing on his nomination. Sometimes a hold on a nomination is simply a way of trying to extract some specific policy change or administrative action from the executive branch. For example, the Hill reported last year that Sen. David Vitter, R-La., announced he was lifting his hold on Obama's nomination of Dan Ashe to head the Department of Interior's Fish and Wildlife Service. Vitter wanted speedier action from the Obama administration on approving deep-water drilling permits in the Gulf of Mexico. "I said I would lift it when we got to 15 permits," Vitter said on June 1, 2011. We finally reached that mark today, and I'm lifting my hold. But the stakes would be far higher if Obama nominated Rice, partly because it would be the first nomination battle since he won re-election last month. NBC News's Domenico Montanaro contributed to this story.