Republicans Battle: Marco Rubio trashes Donald Trump for profanity; John Kasich says Jeb Bush is too "negative"

As the GOP race is tightening ahead of the South Carolina primary, Marco Rubio is slamming Donald Trump for calling Ted Cruz a "p*ssy." Meanwhile, John Kasich is going after Jeb Bush for his "negativity." Real Clear Politics national political reporter Caitlin Huey-Burns joins CBSN the Republican candidates' strategies moving forward into South Carolina.