Rep. Adam Schiff (D-Burbank), said going to places such as the Glendale Galleria and hearing the unvarnished views of constituents is critical to representing the district.
"I am not willing to give it up, and I don't think my colleagues should, either," Schiff said.
Jo Maney, spokeswoman for Rep. David Dreier (R-San Dimas), whose district includes La Cañada Flintridge, said the Giffords shooting was "an attack on our system of government, on people participating and exchanging thoughts. Mr. Dreier has made it clear that this event will have absolutely no effect on his ability to do his job."
Glendale Police Sgt. Tom Lorenz said he can't disclose specific security measures for VIPs, but said high-profile events in Glendale are nearly a weekly occurrence. In October, President Obama and First Lady Michelle Obama visited Glendale on separate occasions, and gubernatorial hopeful Meg Whitman was met by a rowdy crowd at Porto's Bakery just before the November election. High-profile entertainers routinely come to the city.
Lorenz said police work closely with federal and state authorities on intelligence and tactical strategies, and Glendale police also consult with movie studios and publicists on celebrity events.
Officers are trained on protecting dignitaries, and the department's SWAT and K9 units also have expertise in event security, he added.
"It is not only an effort to protect our elected officials or people appointed to local or federal office, but it is to protect community members, too," Lorenz said. "We want to make sure that those who want to enjoy their 1st Amendment rights are safe."
While the man charged in the Tucson shooting, Jason Loughner, appears to have acted on beliefs outside the political mainstream, Schiff and Sherman said the tenor of political debate in the country has deteriorated.
Sherman said that during the health-care town hall meetings in 2009, there was an organized effort to "create an atmosphere of lawlessness," and that he has hosted meetings on Israel and other topics that drew volatile demonstrators.
A few years ago, he said he asked the Los Angeles Police Department for help at one event.
"We showed them some e-mails we received and convinced them [to come]," Sherman said. "I don't think I'll have that problem next time."