Chris Hayes on Politics; Gettysburg; Pacific by Tom Drury; Please Explain

MSNBC host Chris Hayes talks about the push to pass immigration reform, the NSA scandal, and why so many Americans have lost trust in their government. Then, as the 150th anniversary of the battle approaches, we’ll look at Gettysburg and why it was a turning point in the Civil War. Tom Drury discusses his latest novel, Pacific. Plus, this week’s Please Explain is about pain and how the body responds to it in many different ways.