Story highlights A Mexican immigrant faced a backlash after being photographed with Donald Trump

Angry online commenters and callers threatened Betty Rivas and her restaurant

Catalina, Arizona Donald Trump scored a 22-point victory in the Arizona Republican primary on Tuesday, but even as the billionaire's campaign turns its attention to upcoming contests, a political proxy battle has erupted here, about 90 minutes north of the border with Mexico.

The unlikely arena is a small restaurant a few miles outside Tucson, in the shadow of the dusty Catalina Mountains, called "Sammy's Mexican Grill."

On Wednesday evening, its narrow dining room was packed and the drive-thru temporarily shuttered in deference to in-store traffic, which had tripled over the past 24 hours -- as a viral image of its owner at the side of the controversial GOP front-runner roiled a community and set off a firestorm online.

It had been a little more than four days since Betty Rivas, who owns "Sammy's" with husband Jorge, placed herself a few feet from the stage at a Trump rally at the nearby Tucson Convention Center. It was, she told CNN, "a perfect location."

Trump spotted Betty, a Mexican immigrant, as she waved a sign reading, "LATINOS SUPPORT D. TRUMP." About halfway through the event he called her up to the podium.

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