Libertarian Party candidate for president Gary Johnson, left, a former New Mexico governor, and vice-presidential candidate William Weld, former governor of Massachusetts, respond to questions during an interview in the SLS Las Vegas Thursday, Aug. 18, 2016.

Steve Marcus

Libertarian Party candidate for president Gary Johnson, left, a former New Mexico governor, and vice-presidential candidate William Weld, former governor of Massachusetts, respond to questions during an interview in the SLS Las Vegas Thursday, Aug. 18, 2016.