all right, since the terror attacks in paris one week ago, the fight against isis has become a major election issue in the u.s., but it's what some of the candidates are saying that is fueling a debate about the fight on terror and how the u.s. should deal with refugees. our sunlen serfati is following that story. >> very simply, we can't take them, folks. we can't take them. >> reporter: it's a debate roiling in the republican party. how to handle the resettlement of syrian refugees in the wake of the paris attacks. donald trump drawing a hard line, refusing to take any option off the table to protect the u.s., including closing some mosques in the u.s., issuing muslims special i.d. cards, listing their religion, and potentially creating a database to register and track all muslims living in the u.s.