After all of George Lopez's experience in stand-up comedy and sitcom production, it was only natural that he would combine his love of social commentary and comedy for a late-night talk show. In 2009, George Lopez began hosting his very own late-night talk show on TBS called "Lopez Tonight." It aired Monday through Thursday and ran for two seasons. During the second season, Conan O'Brien's show threatened to push back Lopez's time slot to the midnight hour. O'Brien wasn't necessarily comfortable with this (via The Atlantic), but Lopez advocated for it and felt it would be fine to push it back. He was fighting for an audience with ABC's Jimmy Kimmel, and that time slot was already very competitive.
However, the competition proved to be too much, as Lopez's viewership went down by nearly 40%, according to a report from USA Today. Like the cancellation of "George Lopez," finances were cited by TBS as a reason for canceling the late-night show, even though Lopez's budget was already much smaller than that of O'Brien, Fallon, and other popular comedians.
According to a report from Salon, another reason "Lopez Tonight" didn't work was because it was initially created as a tester for TBS to see if they could hold their own in the late-night arena. Once they clinched O'Brien to their lineup, he was the real draw for late-night entertainment, whereas Lopez was becoming an unnecessary expense to the network. Of all the reasons "Lopez Tonight" failed, ultimately O'Brien's arrival on TBS was the biggest.