Welcome to Trail Guide, your daily tour along the road to the White House. It's Friday, Aug. 28, and this is what we're watching:
- Scott Walker is set to deliver a foreign policy speech at the Citadel in Charleston, S.C.
- Marco Rubio is also in The Palmetto State – not far from Walker — where he'll specifically be discussing U.S.-China relations
- Democrats are in Minneapolis for their summer meeting. Former Maryland Gov. Martin O'Malley is among those to address the gathering
- Guess what? Donald Trump still leading in the polls for the Republican presidential nomination
- In Iowa, Rick Harrison, star of History's Pawn Stars, will help open Rubio's Iowa offices