Welcome to Trail Guide, your daily host through the wilds of the 2016 presidential campaign. It's Monday, Sept. 21, and this is what we're watching:
- Hillary Rodham Clinton travels south, where she will roll out her proposed changes to Obamacare with stops in Baton Rouge, La., and Little Rock, Ark.
- Texas Sen. Ted Cruz is the latest 2016 candidate to appear on "The Late Show" with Stephen Colbert
- Ben Carson made a startling assertion: No Muslim should be president
- Stay up to date on the 2016 field and explore their strengths and weaknesses with this Times graphic
Carson advisor: 'Nothing to apologize for'
Ben Carson has no need to apologize for saying the U.