One of the worst things that can happen to a campaign is to have cash flow problems. Trump's campaign is apparently have those problems as evidenced by the campaign's manager pulling back on paid advertisements. This is an indication of cash flow issues and a shortage of cash to fund campaign advertising operationsn.
This close to an election, this issue is not a good one for any campaign to experience.
(The Washington Post) "The decision to slash spending has been ordered by Trump’s new campaign manager, Bill Stepien, who has been restructuring the budget since taking over the campaign operation in July, after it had already spent nearly $1 billion.
Stepien has told others that cutting the ad budget was necessary because it was impossible to cut other spending, such as staffing or a campaign headquarters. He has described facing difficult choices, as he tries to save considerable money for the final 30 days before the Nov. 3 election."
The last 30 days of a campaign are crucial. Money is the coal that will drive the campaign train and without the coal you will lose. Right now, the Trump campaign is in a bad position.
Read: Republican worries rise as Trump campaign pulls back from television advertising by
Michael Scherer, Josh Dawsey of The Washington Post