This is more confirmation of what we already knew. They have to lie to get traction. From the DNC email leak (email from Brina Milikowsky, Chief Strategy Officer, Everytown for Gun Safety to Shannon Watts, forwarded to firstname.lastname@example.org):
Donald Trump has made a lot of promises, but most voters haven’t heard this one yet: He has publicly vowed that on day one of a Donald Trump presidency, he will force every elementary and high school in America to allow guns… 
1. “Donald Trump: ‘I will get rid of gun-free zones on schools’,” Jenna Johnson. The Washington Post, January 8 2016.
Getting rid of the Federal law mandating “gun free zones” around schools cannot be construed as forcing “every elementary and high school in America to allow guns”. Have they ever heard of the difference between state law and Federal law?