Presidential candidates Newt Gingrich and Ron Paul have committed to a forum in Aiken on Tuesday, sponsored by the Aiken County Republican Party, said K.T. Ruthven, the party’s executive committeeman.The forum will be held at the USC Aiken Convocation Center. The doors will open at 5 p.m., with the program beginning at 7 p.m. Each candidate will get an opportunity to answer the same three to five questions.Two other contenders, Rick Perry and Rick Santorum, are trying to arrange their schedules in order to attend, Ruthven said."We’re assuming we’ll have at least four candidates, and we’re trying to reach out to Jon Huntsman, too. After Mitt Romney appeared in Aiken (Friday), we hope he will see Aiken as a big enough venue to come back for the forum," Ruthven said.