Churchill Downs, Inc. (CDI), which in recent seasons has ended racing at such high-profile tracks as Arlington and Calder over alleged profitability issues, on Tuesday threatened to pull out of Fair Grounds over a recent court ruling that bars it from using a certain type of slot machine, saying the ban would cause it to lose money at the New Orleans track and 13 off-track-betting outlets it owns. Reporting by Anthony McAuley and Tyler Bridges at NOLA.com first broke the news, which emerged out of an "emergency" Louisiana Racing Commission...