The question now seems more like one of when rather than if. With vendors going upaid, rumors of a major shake-up of campaign management, and skittish donors the Walker campaign is looking more like a worn out nag hobbling its way to the knacker’s yard than the potential juggernaut it appeared earlier in the year.

Not only has Walker been less than impressive in his debate performances, polls show him losing strength over time. A recent Quinnipiac polls had Walker at 10th of 16 candidates in the must-win state of Iowa.

Walker’s strategy now is to focus heavily on Iowa and see what happens then:

Gov. Scott Walker of Wisconsin is refocusing his Republican presidential campaign on Iowa and South Carolina, where his early popularity in opinion polls has crumbled with the ascent of Donald J. Trump, and he has taken the unusual step of canceling major speeches in Michigan and California this coming week to spend time in those two crucial states.

Mr. Walker, who has fallen in one key Iowa poll from first place in July to 10th place this month, no longer plans to appear next weekend at a prestigious Republican conference on Mackinac Island in Michigan or at the California Republican Party convention. Instead, his advisers said, he plans to campaign in Iowa — where he is holding events this weekend as well — and in South Carolina. (editor’s note: the campaign has put the Michigan back on Walker’s schedule.)

When you start cancelling campaign appearances this early in the season it is never a good thing.

Major donors are starting to hedge their bets with other candidates:

Despite optimistic talk from the Walker camp, his major donors remain unsettled. They have watched their candidate fall from first place in Iowa earlier in the year to seventh, according to theRealClearPolitics polling average.

…

But his donors are reassuring themselves that despite his low standing in polls, Walker is still viewed overwhelmingly favorably by Republican voters, even if he’s not their first choice.

Few of Walker’s donors will say anything negative about their candidate publicly, and even on the campaign’s conference call Thursday, nobody pressed the candidate particularly hard on his performance, a donor who participated in the call said.

“It was pretty polite. … I don’t think anybody’s going to go after Scott Walker on an open phone line,” that donor said.

“[But], I mean, are there behind-the-scenes conversations? Yes.”

The AP adds more details:

But like Hubbard, some of Walker’s biggest financial supporters have spread their largesse from the start, an indication that they’re not committed to him for the long haul.

Robert McNair, the billionaire owner of the Houston Texans, gave $500,000 to a pro-Walker super PAC — and the same amount to groups backing Jeb Bush, [mc_name name=’Sen. Ted Cruz (R-TX)’ chamber=’senate’ mcid=’C001098′ ] and [mc_name name=’Sen. Lindsey Graham (R-SC)’ chamber=’senate’ mcid=’G000359′ ]. Chicago billionaire hedge-fund manager Ken Griffin cut $100,000 checks this spring to Walker, Rubio and Bush.

That’s a smart strategy for donors, Hubbard said Thursday.

“I’m not going to turn my back on Walker,” he said. “I’m still continuing to back him. … But I think it’s good to have a robust team.”

Walker’s SuperPAC has raised substantial funds but his campaign has lagged. Via POLITICO:

But even some Walker allies worry he entered the race too late – in July, just as he began to crater in the polls – and didn’t take advantage of his months of front-running to build up a political rainy-day fund for the current downpour of bad news. Walker has plummeted all to the way to 2 percent in the most recent Washington Post/ABC News and New York Times/CBS News polls.

And now cash flow could be at risk, and his team knows it.

Walker has been on a cross-country push to make sure he doesn’t run out of funds. While his super PAC and nonprofit raised $26 million in the first six months of 2015, Walker didn’t begin raising money within the $2,700 limits for his campaign itself until July and he must fund a sizable staff, in his Madison headquarters, Iowa and elsewhere.

Walker has at least 90 paid staffers who probably burn through $750,000/month in salary and benefits. This cash flow crisis is showing up in vendors not getting paid:

Nervous campaign vendors are currently waiting to be paid more than $100,000 for outstanding debts, according to a person at one of the firms who spoke on the condition of anonymity. The person was not authorized to speak publicly about the firm’s financial relationship to Walker’s campaign.

The person said there is widespread recognition that Walker built a large and expensive campaign infrastructure when fundraising appeared strong earlier in the year. That is leading to fears among Walker’s creditors that he could become this cycle’s Tim Pawlenty, the former Minnesota governor who left the 2012 presidential race deep in debt months before the first votes were cast.

As we reported yesterday, there are very credible rumors that campaign manager Rick Wiley is on the way out (and there are more and more interesting rumors kicking around that should be public in the coming days and weeks*).

As Scott Walker’s presidential bid founders, some in the candidate’s orbit are participating in a whisper campaign against his top strategist and campaign manager, Rick Wiley.

A number of Walker’s donors and supporters have been circulating a rumor about Wiley in recent days, apparently aimed at discrediting him and bringing about a shakeup in the organization, according to two Republican sources. The sources, neither of whom is affiliated with a presidential campaign, said they heard the rumor from people in Walker’s camp. They also said an anonymous letter about Wiley is circulating in political and donor circles, though it is unclear where it originated.

BuzzFeed News could not confirm the details of the rumor, and will not publish it.

Even the though Walker and his staff maintain no changes are in the offing, the Washington Post’s Chris Cillizza writes:

In the wake of the debate came whispers that Walker needed to do something drastic — like jettison members of his senior staff — to show that he could reverse course. He insisted he needed to do no such thing (always the kiss of death) and said no one except reporters had asked him about it.

By some yet unforseen deus ex machina, Scott Walker may survive past Iowa but all indications are that he has entered on a terminal glide path and it will be difficult, if not impossible, to reverse that trajectory.

*

Lots of different people all sending me the same rumor about a particular campaign manager caught indecently at the Ohio debate.

— Erick Erickson (@EWErickson) September 17, 2015