Palin's re-emergence underscores GOP split

Former Republican vice presidential candidate Sarah Palin speaks to a crowd as she introduces Republican presidential candidate Donald Trump at a rally in Tulsa, Okla., Wednesday, Jan 20, 2016. Former Republican vice presidential candidate Sarah Palin speaks to a crowd as she introduces Republican presidential candidate Donald Trump at a rally in Tulsa, Okla., Wednesday, Jan 20, 2016.