Story highlights Donald Trump joked that 'tax problems' required Bernie Sanders to have hernia surgery

Trump also offered to bring back waterboarding and 'go a step further' if he's elected president

Washington (CNN) Donald Trump joked Monday that Bernie Sanders needed hernia surgery because of the heft of the tax hikes his campaign proposals would carry.

Sanders, the Vermont senator and Democratic presidential contender, was off the campaign trail Monday to have outpatient hernia surgery at George Washington University.

"You know why?" Trump asked a crowd in Macon, Georgia. "Carrying around too much tax problems."

Trump continued: "Because he's gonna tax you. He's gonna tax you. But let's not even talk about tax problems -- he wants to double and triple everyone's taxes, wants to bring you up to 90%!"

When asked for a response to the insult, Sanders spokesman Michael Briggs said, "There's not enough time in the day to respond to every dumb thing Donald Trump says."

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