A pair of conflicts ensued over Leno's 22-year tenure, both revolving around the then-current hosts of "Late Night", the program directly following "Tonight" since its premiere in 1982. Original "Late Night" host David Letterman was considered Carson's top choice as successor and left the network acrimoniously in 1993 after Leno was given the job. Years later, NBC attempted to transit Letterman's "Late Night" successor, Conan O'Brien to in turn succeed Leno as host of "Tonight" in 2009. However, as a result of various contractual obligations and fears of losing performers to other networks, Leno was given a nightly prime-time show shortly after Conan's run began. Leno posted less than stellar ratings, leading to a domino effect on the late local news. O'Brien's "Tonight" also suffered falling ratings leading to a public controversy that resulted in O'Brien leaving the network the following year, and Leno returning to host "The Tonight Show".