But they may be stymied if their anticipated protests get too loud or impede anyone's access to the pro-Walker event, as its organizers have already laid claim to the same turf the protesters want to use.
We Are Milwaukee, the consortium of labor and social-left groups that organized and staged a Recall Walker rally and signature-gathering event Nov. 15 in Wauwatosa, has calls for protests on its Facebook page.
The group also created an events page on Facebook called Stand Against 1% Walker to promote a protest, but in the past 24 hours it has been largely taken over by posts and comments from Walker supporters.
The page includes a poster and text publicizing a protest from noon to 3 p.m. Saturday in Hart Park. It calls for protesters to gather at North 70th and Chestnut streets, which is within the park and immediately west of the area being barricaded off for Celebrate Walker.
However, Onward Wisconsin, the political action committee formed to plan and promote Celebrate Walker, has also rented that part of the park stretching all the way to North 72nd Street.
That would put anti-Walker protesters at 70th and Chestnut squarely in the middle of a reserved area — reserved by their political opponents.
Onward Wisconsin spokesman Paris Procopis said that his group does not currently plan to barricade the area between 70th and 72nd streets and will not expel anyone who does not go overboard trying to disrupt their event.
If there are serious disruptions, though, event organizers might act to remove people, he said.
"We reserve the right to exercise our permit," Procopis said. "Everyone has heard their message; now it's our turn to be heard."
Procopis acknowledged that no one can reserve the sidewalks along 70th Street, only the park commons, and that if protesters stick to the sidewalks and don't impede anyone's access, they will likely not be challenged. But he said that police had told his people they would act as necessary to protect the public safety.
Efforts to reach individuals identified as protest organizers were unsuccessful.
Ted Kraig of Council 10, representing teachers in a number of west and south suburban school districts, was a co-coordinator of the November recall rally but said he was not involved in organizing an anti-Walker rally on Saturday.
Kraig confirmed, however, that a protest effort was being planned by other members of We Are Milwaukee. He said that the lead was being taken by Peter Rickman, who also was a coordinator of the November recall petition rally.
Rickman did not return phone calls Wednesday.
An anonymous e-mail forwarded to Wauwatosa Patch referred to gathering a group of protesters outside the park and then entering the park for a picket line and protest rally. It called for recipients to forward the message through their networks.
Walker fans are taking a wait-and-see attitude toward the possibility of a turnout of protesters confronting them. With a lot of big names on stage and a crowd of 1,000 or more to protect, though, they and police will keep a close eye on the situation.
"This grass-roots event was born of a small group of people united through social media and bound by a passion for politics," said Meghan Duffey, a coordinator of Celebrate Wisconsin. "It is our intent to exercise our First Amendment right by collectively expressing our freedom of speech, as many others have in Madison.
"All we ask is that the left respect our rights, as we respect theirs by not ruining their gatherings with unruly counter-protesting."