call them at their columbia office number
leave a message with their secretary and ask them to get them the message today.
http://www.scstatehouse.gov/html-pages/senatemembersd.html
Go to the statehouse website, look up as many sc senators representing your area and their gressette building phone numbers. Call the number, and a secretary will answer. Tell her to take down this message to give to the senator immediately:
“This is ________ from ______. I own _________ business. We really need the Senator to co-sponsor S.1386 today. It is pending third reading on their calendar for tomorrow and in order for it to matter to Congress and our u.s. government policy makers, it needs every single coastal senator in south carolina to be sponsoring it.”