Hide Caption 18 of 22 Photos: Scott Walker's career Walker holds up a 'Wisconsin is open for business' bumper sticker as he speaks during a ceremonial bill signing outside his office at the Wisconsin State Capitol on March 11, 2011, in Madison, Wisconsin. Scott Walker dropped out of the GOP presidential race Monday evening, urging other candidates to do the same so voters will coalesce around a candidate who can topple front-runner Donald Trump.  Scott Walker is now officially out, announcing at a press conference Monday that he was withdrawing from the presidential contest so that a “positive conservative message can rise to the top of the field” and buttress the current frontrunner, Donald Trump. He urged others to do the same to give voters a choice among a limited number of people who can offer “a positive conservative alternative to the current front-runner.” 
 
 Walker’s candidacy, like those of other elected and former elected officials, began to erode because of the growing support for three non-politicians — Trump, retired neurosurgeon Ben Carson and former Hewlett-Packard chief executive Carly Fiorina. Hide Caption 2 of 22 Photos: Scott Walker's career Walker speaks at the annual Conservative Political Action Conference at National Harbor, Maryland, outside Washington, D.C. on February 26, 2015. As Walker was calling it quits during a news conference at home in Wisconsin, his national finance co-chairman, Anthony Scaramucci, was fielding calls from five campaigns — including from three candidates themselves.  Before there was Donald Trump or Ben Carson or Carly Fiorina, there was Scott Walker — a defiant outsider who portrayed himself as the regular-guy champion of the GOP’s burn-the-Beltway base. He sounded "upbeat," they said, and his message to supporters was, "I did the best I could." Almost everyone (except Ted Cruz and Jeb Bush) has changed positions in this race. His prospects further soured on Sunday, when a CNN/ORC International Poll found him receiving the support of less than 0.5 percent of Republicans nationally after the second debate last week, where he spoke the least of the 11 candidates on the prime-time stage.
– Scott Walker is out of the GOP race after a campaign that peaked well before it officially began: He led the polls in Iowa for much of the year, but he has dropped out of the race after just 71 days, which ABC News reports is one of the shortest modern presidential campaigns on record. Where did it all go wrong for the Wisconsin governor? Insiders tell Politico that Walker was overconfident, and though he tried to act as his own campaign manager, he seemed to be "making it up as he went along," causing plenty of strategic blunders. Fundraising dried up as Donald Trump's rise pushed him to the sidelines, leaving him with a large organization but little support. His sudden departure from the race came after he failed to make an impression at the second debate and a CNN poll found his support at well below 1%. "He was a terrible candidate, but he also got Trump-ed," a source tells Politico. More: Sources tell CNN that although a super PAC supporting him had plenty of cash, Walker's campaign funds started to dry up after the first debate as donors looked elsewhere. Walker "is a pragmatist above all else and just didn't see the path to a comeback" after his poll numbers collapsed even in Iowa, a campaign insider says. Walker was hurt by flip-flops on issues like birthright citizenship, where he changed his position three times in a week, CNN notes, and by gaffes like suggesting he would consider building a wall along the Canadian border. In his exit speech last night, Walker said he had been "called to lead by helping to clear the field in this race so that a positive conservative message can rise to the top of the field." He urged other candidates to follow his lead so a clear alternative to Trump could emerge, the Washington Post reports. Some of Walker's former rivals praised him as he left the race, including Marco Rubio, who called him "one of the best governors in the country," and Donald Trump, who said "he's a very nice person and has a great future," reports the Hill. The rival campaigns didn't wait until Walker announced his exit to start trying to poach his aides and his donors, the AP reports. The competition heated up after the announcement: A source close to the billionaire Ricketts family, which had supported Walker, tells the AP that within minutes of the governor's press conference, the family received calls from six campaigns, some of them from the candidates themselves. (Rick Perry has also dropped out of the race, and one donor wants his $5 million back.)