Councilman Matthew Harper introduced the ban in response to a similar law for county recreational facilities passed in April by the Orange County Board of Supervisors. That ordinance allows sex offenders to visit county beaches and parks with permission from the Sheriff's Department.
Harper, who works for Supervisor Janet Nguyen, said Huntington Beach cannot sit idly by and allow sex offenders to gravitate here as its neighbors ban them.
But such laws are considered punitive, Chemerinsky said.
"The system has always been inconsistent about that," he said. "On the one hand, there's a strong notion that once you served your sentence, you paid your debt to society and you should be an equal participant. But there are also many ways in which those who have been convicted of crimes and have been released will suffer lifelong consequences."
There is also a practical question of how to enforce a law in a city that draws thousands of tourists to its beaches, Councilwoman Connie Boardman said.
"How would you know if someone was a sex offender?" she said. "Why are we singling out sex offenders? Why not murderers, why not drunk drivers, why not thieves? We have a problem every summer with people losing their stuff at the beach."
Boardman noted that studies show that 90% of the children who are assaulted know their attackers.
"This is not about statistics, it's about protecting the citizens of Huntington Beach," countered Mayor Joe Carchio.
Orange County Deputy District Atty. Brian Fitzpatrick, who urged passage of a law in Huntington, said the county ordinance closes loopholes that allow sex offenders to hang out where children gather.
Out of 141 reported sexual assaults last year, six happened at the beach or in parks, Huntington Beach Police Chief Ken Small said.
But even with the ordinance, police would investigate suspicious behavior the same way they do now, Small said.
"The problem is there's such a strong emotional appeal to this type of legislation, it's hard to speak against it without looking or sounding stupid," Small said.
Convicted sex offender Floyd Harper, 64, of Huntington Beach, said he was young and stupid when he committed a sex crime in 1973 and has since had psychiatric treatment and is no longer a threat.
Harper, who is not related to the councilman with the same last name, doesn't go to the beach because of a bout with skin cancer but said he wishes the law would distinguish between violent criminals and those like him who have turned their lives around.
"I guess it is what it is," he said. "But I don't think it should apply to everybody."