Woe betide the guest who stands up David Letterman. When Arizona Senator John McCain canceled his Sept. 25th appearance on The Late Show to deal with the country's increasingly erratic economy, Letterman used his monologue to berate the Republican presidential hopeful. "I feel like an ugly date. I feel used. I feel cheap. I feel sullied," he groused. But Letterman's rage reached incandescence when a live feed from another CBS studio showed McCain, rather than on his way to the airport as he'd claimed, being made up for an interview with Katie Couric just blocks away from the Ed Sullivan Theater. For weeks afterward, Letterman would work McCain's cancellation into his jokes. "The road to the White House runs through me," he warned. Less than a month before the election, McCain appeared on the show to apologize, telling Letterman, "I screwed up." But apparently the apology wasn't entirely accepted. "Listen, Senator," Letterman quipped after McCain lost to Barack Obama, "You don't show up for me, America doesn't show up for you."