Bush 41 and 43 REFUSE to endorse Trump: Former Presidents join a growing list of top Republicans who will not back their party's presumptive nominee Both George H. W. Bush and George W. Bush will not back Donald Trump A number of Republicans say they will not back the presumptive nominee Trump has all but secured the nomination after Cruz & Kasich dropped out Senate Majority Leader Mitch McConnell said Trump has the 'opportunity and the obligation' to unite the GOP Former Presidents George H. W. Bush and George W. Bush will not endorse Donald Trump, their spokesmen have announced....