The Tonight Show will air a rerun on May 21 Following Jimmy Kimmel’s lead , NBC will air a rerun of The Tonight Show Starring Jimmy Fallon on May 21 when The Late Show With Stephen Colbert broadcasts its final episode, according to Variety . With no new competition, The Late Show , which CBS canceled after nearly 11 years on the air, stands to be the late-night leader for a final time. Since September 2015, when Colbert took over The Late Show from David Letterman, Fallon and Colbert have been crosstown rivals, both broadcasting late-night talk shows from New York City in the same time slot. Kimmel, who has hosted Jimmy Kimmel Live! for more than a decade longer than Fallon and Colbert, provided competition from Los Angeles. Colbert set himself apart, though, with incisive and brainy political humor, which often propelled him ahead of the others in terms of ratings. That was a difficult feat in the era of attentions divided by cell phone screens.…