Peter Suderman offers an explanation for why Walker has done so badly as a candidate:
Instead, he’s allowed himself to be drawn into a series of news cycle traps, and then handled the aftermath poorly, often by denying that he’d made any misstep in the first place.
Most recently, for example, Walker seemed to suggest that he was open to the possibility of a building a wall along the Canadian border in order to stop illegal immigration. He responded by saying that he’d been asked this question by people in New Hampshire, that the people asking the questions had “very legitimate concerns,” and that the idea of building a wall would be “a legitimate issue for us to look at.”
It’s not exactly a “damn right we should build a wall!” But Walker’s response clearly takes the idea seriously, and pointedly does not rule it out [bold mine-DL].
Walker’s response to that question was just the latest example of his strong commitment to not ruling things out. He first displayed this on the national stage during a Sunday morning show interview in which he wouldn’t rule out sending ground forces into combat against ISIS in Syria. Walker didn’t explicitly endorse doing that, but he thought it was crucially important not to rule it out, because for him there is apparently no course of action so unwise or unnecessary that it should be rejected immediately. This later tripped him up when he was asked if he favored a “full-blown re-invasion of Iraq and Syria,” which he also refused to rule out. I have said before that Walker doesn’t want to rule things out because he hasn’t given much thought to the positions he has taken as a candidate, and that’s probably a main reason why he doesn’t know how to articulate or defend those positions very well.
As Suderman observes, he doesn’t know how to respond to criticism of his ill-advised statements, and so often retreats into denial:
This is the Walker campaign playbook: Say something awkward or ill-advised, watch as the media swarms to cover it, then insist that there was never anything to see.
Walker has to do this because he isn’t prepared to be a national candidate and doesn’t know how to cope with the scrutiny that goes with running for president.