Welcome to Trail Guide, your daily tour through the wilds of the 2016 presidential campaign. It's Tuesday, Aug. 18, and this is what's on tap for the day:
- Donald Trump keeps his lead in the latest post-debate poll of Republican candidates
- Scott Walker will outline a plan to replace Obamacare as he tries to drive both the issue and his candidacy back into the spotlight
- Hillary Rodham Clinton and Bernie Sanders are courting the labor vote at an AFL-CIO state convention in Las Vegas
- John Kasich is the latest candidate to head to the Iowa State Fair
From New Hampshire to Washington state and Nevada, Black Lives Matter activists have confronted presidential candidates, calling on them to address issues such as poverty, racial profiling by police, incarceration and homelessness.