Welcome to Trail Guide, your daily run along the road to the White House. It's Tuesday, Sept. 8, and this what we're watching:
- Democrats and Republicans head into the fall campaign facing opposite questions about enthusiasm, reports Times' David Lauter
- He may not have made up his mind, but Joe Biden was running on Monday, CNN reports
- Hillary Rodham Clinton is still not sorry about her choice of email
- Ben Carson will address the Commonwealth Club in San Francisco
- From the archive: A look at Hugh Hewitt and his Southern California roots