Multimillionaire businessman John Warren has opted not to challenge South Carolina Gov. Henry McMaster to a rematch of their 2018 GOP primary face-off. Warren said Thursday that he'd sit out this year's election to focus on the Bitcoin company he launched last year. There had been speculation Warren would mount a redo of 2018, when the businessman leveraged more than $3 million of his own money to fund his challenge of McMaster and force the incumbent to a runoff.