09/21/2015 07:50 EDT | Updated 09/21/2015 07:59 EDT

Scott Walker, Presidential Candidate Who Wanted To Build Wall With Canada, Pulls Out Of Race

WASHINGTON — He talked about building a wall with Canada. What he found was one around the White House.

The barrier to Scott Walker's presidential dreams went up quickly.

The Wisconsin governor has ended his presidential run after a spectacular collapse in his bid for the Republican nomination, where in the span of just a few months he went from possible front-runner to zero per cent in a national poll.

"I was sitting at church yesterday. The pastor's words reminded me that the Bible is full of stories about people who were called to be leaders in unusual ways," he said Monday.

"Today, I believe that I am being 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.

"With this in mind, I will suspend my campaign immediately."

He urged some of the other dozen-plus candidates to do the same. Walker said it's time for Republicans to rally around a positive, hopeful alternative to the current front-runner. He didn't speak the name of his apparent target, Donald Trump.

Walker's problem of microscopic poll numbers was compounded by infighting within his campaign, as rivals leaked to the media complaints about each other and occasionally about the candidate himself.

As obituaries of his campaign piled up in recent weeks, his remarks about Canada were a frequent theme.

The consensus of the Washington punditry was that Walker struck another nail into the pine box of his presidential aspirations when he fumbled a recent question on an NBC talk show.

An interviewer asked why he kept talking about walls with Mexico and not Canada - which has had terrorists. Walker's reply? A wall with Canada was a legitimate idea. He later clarified that, no, he didn't favour building one.

A subsequent piece in the Washington Post was among many that listed this episode as further evidence of his unreadiness for prime time: "Walker's performance as a candidate has contributed to questions about the trajectory of his campaign. His verbal missteps ... have been a topic of concern among his own loyalists."

The piece mentioned the Canadian wall idea, along with a simultaneous flip-flop on whether he supported ending the practice of citizenship-by-birthright.

Similarly, he wavered over how to handle seemingly easy questions from media about whether President Barack Obama loves the United States and is a Christian.

It was a spectacular fall for a candidate with a CV right out of Republican central casting.

The son of a preacher with an oft-stated admiration for Ronald Reagan, Walker was seen as a potential consensus candidate between the various factions of the party: pro-business, tea party, evangelical Christian.

As governor of Wisconsin, he'd busted unions and won three elections - two general votes and a recall. In that time span he'd stripped collective-bargaining rights for public-sector workers, and then private-sector unions, and survived monster protests at the state capitol.

In both cases, he surprised his foes and allies alike because he'd never declared those intentions during his campaigns and in the case of private-sector unions had even explicitly denied planning such a move.

But he received the verbal and financial support of the Koch brothers, the sprawling family empire with a long-standing interest in libertarian and conservative politics.

He hit an early bump in the road in March.

Leading the polls in the Republican field, Walker spoke to an enthusiastic crowd at a conservative conference in Maryland. He was asked what made him prepared to tackle foreign-policy challenges like ISIS. His reply referred to his union fight: ``If I can take on 100,000 protesters, I can do the same across the globe,'' Walker said.

The glare of front-runner's scrutiny didn't help.

Walker lost almost one-third of his support over the month of April, quickly tumbling from 17 per cent atop the field to 12 per cent in an average of polls by Real Clear Politics. The decline gathered speed after Trump entered the race, and the latest poll by CNN last week showed him at zero per cent nationally.

Trump rubbed salt in the wound at last week's Republican debate.

He poked fun at Walker over his state's expanded budget deficit: "That's not a Democratic point. That's a point. That's a fact. And when the people of Iowa found that out, I went to No. 1 and you went down the tubes.''

In the end, he didn't even make it to Iowa. He's the second GOP candidate to drop out, after former Texas governor Rick Perry.

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