Manchester, New Hampshire (CNN)A super PAC spending millions of dollars to bash Ted Cruz's Republican rivals is shielding the names of many of its top donors and strategists, accepting and directing donations through a particularly high number of hard-to-trace companies, new documents reveal. Stand for Truth, Inc., an emerging player in the orbit of often clashing constellation of pro-Cruz super PACs, recently pledged to air more than $4 million in television ads to back Cruz in Iowa and South Carolina. Super PACs can accept unlimited contributions but are required to disclose their financial backers. The twist here is that Stand...