Hoffa’s Union (Union Rags), an impressive maiden winner at Laurel who was subsequently privately purchased and transferred to trainer Mark Casse, is being pointed toward the Mar. 30 GI Xpressbet.com Florida Derby, Casse said Thursday. Originally picked up for $11,000 at Fasig-Tipton Midlantic, the gelding debuted at 1 1/16 miles Feb. 28 and blew away