There is growing evidence that Donald Trump's mud-slinging is tarnishing his gold-plated name, and industry observers say the Republican presidential nominee risks doing permanent damage to his brand.

"There are certainly groups and event planners shying away [from Trump-related venues] just because they don't want to offend anybody," said David Loeb, managing director and senior real estate research analyst at Robert W. Baird & Co.

Already, the Susan G. Komen Foundation is considering relocating an annual fundraiser held at Trump's Mar-a-Lago Club in Palm Beach, NBC News reported. In addition, the PGA announced this summer that it was moving the WGC-Cadillac Championship from the Trump National Doral in Florida to Mexico City next year.

"The majority of the meeting planning community is female, and when you have a candidate who's been very polarizing… it just kind of makes sense that might impact their decision-making," said Kevin Iwamoto, a senior consultant at GoldSpring Consulting. "Planners and buyers are going to vote with their dollars."

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