It's the superpacs of McCains and Graham's that are running and financing the attacks on Trump.
There's BIG MONEY on the table against Trump... and there's bigger money to be made in the legal 'graft games' insiders play... Trump's not going to pay for military weapons we don't want and don't need and costs billions. Trump won't accept bribes - oops I mean ‘donations’ from these crooks. That might be where the heat's coming from...
By all accounts there is now definitely enough money on the table to attack Trump. With all the candidates that dropped out there must be Super PAC money floating around. That’s why Koch decided to stay above the fray, IMO.