WASHINGTON (AP) -- For Scott Walker, it wasn't one thing that led to the demise of his presidential campaign. It was just about everything.
Financial troubles. A bloated staff. Repeated stumbles and flip flops. A candidate that professed to be a fighter, but too often, didn't show all that much fight.
The Wisconsin governor, who dropped out of the Republican race for president on Monday after only two months as a formal candidate, did so after making a litany of mistakes and missteps that could make for a "what not to do" manual for future candidates.
Walker entered the 2016 race as an ostensible Republican darling, shot into the national spotlight by his victories over unions and his triumph in a recall election. With Midwestern appeal and conservative credentials, and buoyed by a rousing performance at a Republican forum in January, he rose to the top very of early polls in Iowa.
That moment in Iowa proved to be Walker's high point. As presidential primaries so often reveal, gleaming resumes don't equal votes or big fundraising totals. And early favorites can quickly fade.
"The support he had was relatively soft," said Republican Wisconsin state Sen. Luther Olsen. "He was at the top essentially because of one speech."
To some extent, Walker is a victim of a campaign in which voters long-frustrated with politics are turning their backs on candidates with long resumes in government. Walker insisted that he, too, would "wreak havoc" on Washington, but he was drowned out by bombastic billionaire Donald Trump.
But Walker's problems were broader than a mismatch with the electorate's mood and were foreshadowed even during his campaign's heady early days.
On a February trade mission to Europe meant to bolster his foreign policy credentials, Walker refused to answer questions about international affairs. He also punted on a question about whether he believed in evolution.
That shallow foreign policy experience and inability to deftly handle questions became more pronounced as the campaign went on.
He was widely panned for arguing that his experience fighting unions in Wisconsin had prepared him for defeating the Islamic State in Syria and Iraq. He said it was "legitimate" to discuss building a wall along the U.S.-Canada border. And he gave three different answers about his position on birthright citizenship in a week.
Even his efforts to separate himself from Washington fell flat. At one point, he said he isn't a career politician — despite having held elected office for 22 straight years.
"The glare of the klieg lights came early for Walker and it's hard to be prepared for that type of scrutiny when it's your first presidential campaign," said Kevin Madden, who advised Mitt Romney during his second run for president in 2012.
Walker also suffered from strategic and structural campaign blunders. While Iowa and its kickoff caucus gave Walker the best chance to grab an early victory, his campaign built a wide network of staff and consultants in states that don't vote until well into March.
But running a national campaign is costly, and Walker and his team burned through cash faster than they could raise it. Even as donors began to grumble about the expensive operation, Walker's team resisted scaling back or trimming salaries.
Walker's admission last week that he was shifting course and putting "all our eggs in the basket of Iowa" was a sharp departure from his campaign's confident predictions earlier in the year about plans to rack up delegates throughout the South and Midwest late in the primary contest.
In addition to refocusing on Iowa, Walker's campaign made a last-ditch effort to energize Republicans by reaching back to the issue that had made the governor one of his party's brightest White House hopes. He unveiled a sweeping blueprint for upending labor unions nationwide, a plan so aggressive that it was even criticized by some Republicans.
Then Walker took the stage in last week's second Republican debate. His union plan garnered no mention from moderators or rival candidates, and Walker didn't even bring it up himself.
Walker needed a standout performance in that debate, one that would validate his assertion that he was a Washington outsider with a fighting spirit. Instead, he generated the least amount of speaking time of the 11 eleven candidates on the stage and gave middling responses when attention did turn his way.
The final blow came Sunday, with the release of a new CNN/ORC poll. While polls at this early stage of the race are often fickle, the message to Walker was unmistakable, according to one campaign aide, who insisted on anonymity in order to discuss the team's internal thinking.
Walker, who had once led the GOP field, was registering less than one percent of voter support. His standing as a White House candidate had been reduced to an asterisk.