When Norm Macdonald was fired from his role anchoring “Weekend Update” on “Saturday Night Live” in early 1998, there was little recourse for his hard-core fans.

Social media did not exist, so they were forced into a decidedly low-tech response. “Time magazine had this thing,” Mr. Macdonald said. “If you wanted to keep Norm going, you had to clip out a coupon and send it to NBC.”

If only Twitter had been around then, he mused. Of course, since the executive then running NBC Entertainment, Don Ohlmeyer, had declared him “not funny,” even a groundswell of support might have made no difference, he conceded.

Maybe it will now. In what has amounted to an unabashed “remember this name” plea, Mr. Macdonald has, over the past month, been at the center of a concerted campaign to enter his name into the running for the last remaining vacancy after the recent upheaval in late-night television.