 The first congressional hearing into the assassination attempt on Donald Trump starts today. Secret Service Director Kimberly Cheadle will testify before the House Oversight Committee. Here is that committee's chair, James Comer, a Kentucky Republican, yesterday on Fox News Sunday. What went wrong with an agency that has a no-fail mission? NPR congressional correspondent Claudia Grisales has been covering the investigations into the shooting. So what do you expect to hear from Cheadle today?