An ally of Hillary Clinton is challenging Donald Trump to release his tax returns — in return for a $5 million donation to a veterans' charity from an unnamed Republican donor,David Brock, who runs the pro-Clinton super PAC Correct the Record, said Trump will get to name the charity he wishes to benefit but has to release the returns by a certain date.Details of the provocative offer will be released Wednesday morning, The Hill reports."The effort represents an opportunity to fill in some of the unknowns about Trump including how much he has made off of potentially fraudulent ventures and how much he’s actually paid in taxes," an associate of Brock's, Erin Bzymek, said in a statement, The Hill reports.he's got to wait for the audits on his returns to be finished before he'll release them, an assertion that has drawn criticism from Democrats, and even