In the feverish final swing of Donald Trump’s campaign, I found myself returning to the same ritual, rally after rally. I’d get off the press charter plane and arrive to find thousands of clamoring supporters eager to see Donald Trump elected the next president of the United States. I’d marvel at the numbers of supporters in attendance, their wild enthusiasm and optimism about their candidates’ prospects, and then I’d get back on the plane, flip open my laptop and toy with the Electoral College map on the 270-to-win website. I turned blue and purple states red as I tried to envision the most plausible path for a Trump victory. And each time, I found myself setting aside the crowds I witnessed and the thick, yet fleeting, aura of “momentum” I had felt at the rallies, and like many others inside and outside the bubble wound up saying: There’s just no way. But, obviously, there was a way. The question then became: What did we miss? I began covering Trump’s campaign in the months leading up to his announcement on June 16, 2015, and stayed with him ever since, racking up hundreds of thousands of flight miles, visiting 43 states, attending hundreds of rallies and speaking with hundreds more voters. And while the reporters like myself on the ground in the early months of 2015 quickly sensed that Trump’s candidacy was more than just a fleeting moment, none of us predicted then that he would go on to clinch the Republican nomination – much less the presidency. In the final months of the campaign, Trump strained to become the polished presidential figure many believed he needed to become to catch the eye of independent voters, while controversies dogged his campaign. A damning 2005 tape of Trump bragging about being able to grope and kiss women without their permission surfaced, and the following week nearly a dozen women spoke out to accuse Trump of the very same behavior, which amounted in many cases to allegations of sexual assault. How Donald Trump won Through it all, the supporters who attended his rallies by the thousands overwhelmingly declared that none of it mattered to them – at least, not enough to make them switch to Hillary Clinton, whom many believe to be corrupt and guilty of crimes related to her use of a private email server. And through it all, most continued to predict their candidate would win – polls be damned. In the final days of his campaign, Trump took on an aggressive schedule, jetting to 10 states to hold 14 rallies in just the last three days. Several of those were particularly startling in size and enthusiasm. A prime example was in Minneapolis, a Democratic city in a blue state, where overflow crowds hanging on the sides of the airplane hangar where Trump delivered his remarks more than doubled the size of the crowd inside. In Sterling Heights, Michigan, a packed crowd roared through the amphitheater as Trump emerged on stage. On Sunday evening, as Trump ran two and three hours late to his rallies, he was still met with packed houses in the suburbs of Detroit, Pittsburgh and in Leesburg, Virginia. But Trump has had large crowds since the inception of his campaign – and it was difficult to discern, especially in light of the polls, that this was anything different. Trump finished within 1 percentage point of Clinton in Minnesota and barely eked out a victory over Clinton in Michigan. He clinched victory in Pennsylvania, where he had been essentially written off, and came much closer than expected in Virginia. Campaign staff I encountered in the final days seemed hopefully optimistic, pointing to the momentum and energy they were feeling. “We’re going to win this thing,” a campaign staffer involved in get out the vote efforts told me Friday. Michael Glassner, a senior Trump aide who joined the campaign in July 2015, also predicted a victory. “We were told for a year that there was no chance that he was going to win the nomination. Everybody said that to me all day every day. I never believed that and they were wrong,” Glassner told me in a phone call early last week. “Everybody says we’re going to lose and I don’t believe it. I never have.” As Glassner predicted, the polls were wrong and of course, so were the pundits. RELATED: What Trump has said about the world But many of Trump’s own staff were also wrong. Arriving at Trump’s election night party Wednesday night, many campaign staffers quietly acknowledged that defeat was the likeliest outcome. A senior Trump adviser told CNN’s Jim Acosta, bluntly: “It will take a miracle for us to win.” And in the campaign’s war room, as political and data staff prepared to pour over the incoming results from polling locations across the country, the mood was dour. “It was not depressing by any means, but it was really quiet. There was not a lot of enthusiasm. Everyone was there just their nose to the grindstone, just working,” said a Trump campaign staffer who spent the day in the room. But at 9:30 p.m., several states began to break Trump’s way and other key battlegrounds were quickly revealed to be too close to call, the race tightening. North Carolina and Florida were at play. Even Virginia seemed within reach. “Suddenly it was like, holy s— we’re actually in a position to do this,” the source said.