Greg Nash Three-fourths of Republicans participating in Saturday's South Carolina GOP primary say they support presidential hopeful Donald Trump's proposal to ban all Muslims from entering the U.S., according to an exit poll. A CBS News exit poll of Palmetto State primary voters found that 75 percent said they support Trump's proposal, while 23 percent said they oppose it. Just days after the terrorist attack in San Bernardino, Calif. - the worst on U.S. soil since 9/11 - Trump sparked a media backlash for saying that all Muslims should be temporarily banned from entering the country. The proposal has...