campaign out with a new ad. >> in times of crisis, america depends on steady leadership. >> knock the crap out of him, would you, seriously. >> clear thinking. >> i know more about isis than the generals do, believe me. >> and calm judgment. >> and you can tell them to go [ bleep ] themselves. >> reporter: the ad argues trump is too unstable when it comes to national security issues. and as trump is now reshaping some of his message he's also started debate prep. sources tell abc news trump will be watching clinton's past

pollute our air. putting their... ...profits ahead of our kids' health. now they're trying to weaken california's clean air laws. i'm tom steyer. we've had a million kids get asthma. we need to send the oil companies a message. tell your legislator to stand up to the oil companies and protect our clean air laws. don't let the oil companies put their profits... ...ahead of our kids.