The Biggest Spender Backing Donald Trump? The NRA.

Why is Donald Trump pandering so hard to “the Second Amendment people”? Possibly because the National Rifle Association is the biggest financial backer of his campaign. The NRA has spent $6 million in TV ads on behalf of the Republican presidential candidate, which is $6 million more than the Trump campaign has spent on itself. (A super PAC, Rebuilding America Now, claimed in June to have $32 million in commitments from four donors, but has only spent $5 million on ads to date. Casino magnate Sheldon Adelson once made a pledge to create his own $100 million super PAC, but as of July has not followed through.)
http://www.alternet.org/election-2016/biggest-spender-backing-donald-trump-nra