The Post was deluged with angry calls for a second day Thursday as marchers carried signs that said "Jail Billionaire N.Y. Post Owner Rupert Murdoch," a reference to the media mogul who owns the Post, the Fox network and The Wall Street Journal.
"We make them and we break them with our money, and we should shut it down," said protester Angela Brown, who carried a glossy photo of Obama.
The drawing by longtime Post cartoonist Sean Delonas shows a dead chimp and two police officers, one with a smoking gun. The caption reads, "They'll have to find someone else to write the next stimulus bill."
The cartoon appeared in Wednesday's Post and refers to Travis the chimp, who was shot to death by police on Monday after it mauled a friend of its owner.
Obama signed his administration's economic stimulus plan on Tuesday.
Protesters said the cartoon echoed racist stereotypes of blacks as monkeys and even suggested that Obama should be shot.
"Since when can you call for the killing of the president of the United States?" demanded City Councilman Charles Barron.
The newspaper has stood by the work, which its editor called "a clear parody" about the killing of the chimp. The Post said it had no further comment on Thursday.
The Rev. Al Sharpton, who led the protest along with Barron and other elected officials and ministers, said there would be another protest in front of the Post's midtown offices on Friday.