With Mitt Romney’s campaign for president nearly in tatters, he huddled with his senior advisers on Wednesday morning, jotting notes with pen and paper, to go over his options. By the time the meeting ended, he seemed to want to stay in the race. His campaign went ahead with voter-turnout calls in Kansas and Washington for caucuses on Saturday, and priced out what it would take to compete in primaries next week in Virginia, Maryland and Washington, D.C.His son Tagg, a senior campaign adviser, urged him to continue, but by evening, Romney had decided to pull out. He then phoned each of his sons individually to break the news.Another son, Matt Romney, said: “I just couldn’t be anything but absolutely proud of him. I’m so proud of his fight.”If Romney’s campaign were condensed to one of his trademark PowerPoint presentations, it would have had all the bullet points foretelling success: a multimillionaire candidate willing to relinquish his fortune to run, an unsettled Republican field and a candidate whose championing of conservative positions could motivate the party’s base.Yet Romney’s advisers acknowledged on Thursday an array of tactical missteps and miscalculations. Perhaps most significantly, they conceded that they had failed to overcome doubts about Romney’s authenticity as they sought to position him as the most electable conservative in the race, a jarring contrast to his more moderate record as governor of Massachusetts. And during the January nominating contests, as his opponents attacked his shifting on issues, polls showed his favourability ratings plummeting. Romney spent more than $35 million of his own money trying to get himself elected, but his campaign faced challenges from the start, some from obstacles beyond his control.Suspicions about Romney’s Mormon faith consumed his campaign early on, only to seem to fade from view. But his advisers and outside experts agree that the unease ultimately helped pave the way for Mike Huckabee, a former Southern Baptist pastor, to emerge from the backbench of the Republican field to win the Iowa caucuses, a central, costly goal of Romney’s strategy. Then Romney’s aides failed to anticipate the collapse of Rudolph W. Giuliani’s candidacy, leaving no one to halt Senator John McCain’s resurgence among moderate Republicans and independents. The authenticity issue was a problem his advisers recognized early on. As Romney was laying the groundwork for his run back in 2006, Alex Castellanos, one of the campaign’s chief media strategists, put together a 77-slide PowerPoint presentation, first reported by The Boston Globe, which listed some of Romney’s vulnerabilities, including the perception of him as an ideological panderer, as well as his Mormonism and his inexperience in military affairs. But his advisers perceived there was a gap in the field for an electable conservative and pounced on that opportunity in recasting Romney’s image. They believed that he could overcome the more moderate views he had espoused in the past as governor of Massachusetts. One of the campaign’s fears all along was that someone would outflank them on the right. Huckabee’s sudden emergence in November still caught many of his advisers by surprise.Meanwhile, the campaign was also attacking McCain over the airwaves, something some of Romney’s advisers said afterward may not have been such a good idea, given McCain’s high favorability ratings across the board in New Hampshire. The attack advertisements paved the way for a devastating counterattack from the McCain campaign, and what many of Romney’s advisers believe was the most effective commercial of the election cycle, a negative advertisement that cited quotes from newspaper editorials to make the case that Mr. Romney was a fake.In the end, even though Romney’s aides contended he found his voice in New Hampshire, he wound up losing the state as well.The campaign chose to make its stand in California, spending $1.7 million in advertising there, as well as a host of states holding caucuses or conventions, and hoped to pick off other primary states, like Georgia or Missouri.