Mitt Romney withdrew from the race for the Republican nomination early this afternoon in an extraordinarily classy speech at the Conservative Political Action Conference (CPAC) in Washington, DC. Romney hinted at the concession at the beginning of his speech and, to the chagrin of the strongly pro-Romney crowd, confirmed it at the end. He spoke directly to comparisons some have made to Ronald Reagan's campaign in 1976, when the California governor fought all the way to the Republican convention in Kansas City. But Romney said these circumstances are different: "We are at war." He spoke of the dangers of electing either Barack Obama or Hillary Clinton, given their repeated calls for withdrawal from Iraq, and said uniting Republicans was more important than pressing on. For those of us who raised questions about Romney's leadership on Iraq and his willingness to put winning there ahead of his political career, he answered those questions rather decisively this afternoon. It's true that the electoral math effectively made this decision for him, but those calculations did not force him to make this speech. Romney's opponents have complained that he ran a tough and negative campaign, and they're right. But he ended it with honor and class.