Tampa police had prepared for the worst.
What they got instead was small crowds of demonstrators on relatively good behavior.
The few protests featured hundreds of people, not thousands. Some demonstrators cursed at police or sat down in intersections, but no one threw bricks into windows.
By evening, no injuries had been reported at the downtown protests; more remarkably, perhaps, only one person had been arrested.
"It's going very well," Tampa police Chief Jane Castor said Monday afternoon, as she rode in an unmarked department SUV in front of about 300 protesters who were holding signs and chanting. "It's very peaceful."
Monday was supposed to be the first day of the Republican National Convention, and technically it was. The GOP met for about 10 minutes to gavel the convention into session, then promptly recessed for the day.
Improving weather and a full convention slate today could mean more demonstrators at the second day of the event.
On Monday, though, organizers of the first big demonstration for the convention were disappointed by the turnout.
"The weather affected us in a negative way," said Jared Hamil, an organizer for the Coalition to March on the RNC. "It didn't work out in our favor."
Hamil said he did appreciate the protesters who showed up at Perry Harvey Sr. Park on Monday morning to brave the wind and rain.
"While the Republicans are hiding away in their hotel rooms," he said, "we have a place to be."
The march once was expected to include as many as 5,000 protesters but only a few hundred protesters, if that many, showed up.
Florida labor organizer Jose Soto said 16 buses of protesters from New York, Miami and the Florida Panhandle canceled because of the storm. He said the bus companies didn't want their equipment and drivers heading toward a possible storm.
Hundreds of police officers dressed in matching khaki uniforms and heavily armed members of the Florida National Guard patrolled the streets.
Protest groups who participated in the march included the Occupy movement, Codepink, Students for a Democratic Society, Veterans for Peace, the Southern Christian Leadership Conference and the Green Party. A few protesters clad in black held a sign indicating they were anarchists.
As the parade rolled through down, protesters chanted as they marched, "Ho, ho, the RNC has got to go."
The crowd marched from Orange Avenue to Nebraska Avenue until they reached a large grassy area surrounded by concrete barricades a few blocks from the Forum. They were followed by hundreds of police officers, who outnumbered the protesters, during the mile and a half walk.
While Tampa's police chief was at the front of the parade route, John Debus of Fort Pierce was at the rear.
"This is where I fell in," said Debus, a retired U.S. Army sergeant, about his place in the march. "I'm here to speak out against greed and corporations. I don't mind as long as I'm getting my word out."
After the scheduled march, an unscheduled one began.
About 100 protesters did a U-turn and made for downtown's "banking district," making police scramble to clear streets and follow the unauthorized march.
During the impromptu march, police arrested one demonstrator, identified as Dominic De La Rosa, 19.
His friend, Keith Cutter, said he and De La Rosa were in the march when police told them both to take off their bandanas. Cutter complied, but he said De La Rosa didn't hear the order. He was taken into custody.
"He's just a kid," Cutter said. "He's harmless."
One of the protests happened at International Mall, away from downtown. Police reported four buses took protesters to the mall, where they chanted and played drums in the parking lot for about an hour. They tried to hang banners on a sign at the mall but stopped when told to by police.
On Monday afternoon, about 100 more demonstrators from a small downtown tent city called "Romneyville" took part in another unpermitted marched to the intersection of Tampa Street and Kennedy Boulevard, where a line of police officers in riot gear stopped them.
The standoff, which had no outbreak of violence, lasted only 30 minutes because a squall from Isaac deluged downtown with heavy wind and rain. About 20 protesters laid down in front of the officers' feet.
Most left when the weathered worsened, but some stayed to dance in the rain.
Reporter Howard Altman contributed to this report
This story originally appeared in the Tampa Tribune.