Honestly, I doubt emails from irate Americans will bother Rondstadt at all. Her carrer is over, she's middle aged and overweight...she appears to be consciously TRYING to rouse the ire of the VRWC so she can play the voctim card, sing at the Democratic Convention and do the talk show circuit.
Within a few days she'll be on CNN, moaning about all the "hate" mail and "threats" she's gotten. And thinking about the FAT paycheck she's getting for appearing.
"Honestly, I doubt emails from irate Americans will bother Rondstadt at all." That's why they are not going to Ronstadt, they're going to the people who book her into their venues. If they believe booking her will cause a PR nightmare and reduced ticket sales, they might reconsider.