we've been talking a lot about how the isis threat will impact the 2016 campaign. marco rubio's campaign is up with its first tv ad of the cycle and it's all about paris and the politics of fear. in what the campaign is calling a major nationwide cable buy, rubio doubles down on his clash of civilizations line from last week, saying, quote, either they win, or we do. >> what happened in paris could happen here. there is no middle ground. these aren't disgruntled or disempowered people, these are radical terrorists who want to kill us. >> we have more on rubio's rhetoric, including the very different ways that rubio and ben carson are now responding to donald trump's claim that arab americans cheered while watching