Plus, in answer to the avalanche of responses in re: the Greatest American Artist of the Twentieth (Thanks Gigi and Luanne!), see below. Looking closely at the center bottom panel, of the prior strip, you can see Ad Reinhardt, hastily caricatured as promised, waiting in line for the Whitney Biennial.
The Greatest American Artist of the Twentieth Century, I tell you.
Also, for further Ad Reinhardt comics images (well worth the time), you can head here (special thanks to Silverstein Gallery for doing the good deed of showing these and keeping the images online).
Ad Reinhardt, of course!
A better poet than Carl Andre (fig. 1, Andre, fig. 2, Reinhardt)
A better cartoonist than Willem deKooning (and Marcel Duchamp, for that matter, but I couldn't find any Duchamp cartoon images):
Also, a painter of some note.
Extra points if you can identify the hastily caricatured deceased art luminary in the crowd (Hint: He's the greatest American artist of the twentieth century). Respond in comments for prizes or congratulations, I'm not sure which.