Jeb Bush himself had been an adviser to Lehman Brothers investment bank. | Getty Former AIG chairman Hank Greenberg invests $10 million in Jeb Bush 01/07/16 07:42 AM EST Updated 01/07/16 12:06 PM EST Billionaire Republican donor Maurice “Hank” Greenberg has donated $10 million to the super PAC backing Jeb Bush’s presidential campaign, according to The Wall Street Journal. The Journal on …