New poll numbers (and polling techniques) surrounding California DP repeal initiative

This local California story, headlined "Poll says death penalty support rises after mass shootings," has interesting poll data and interesting debates concerning the poll data on California's death penalty repeal initiative.  Here are details:

According to one set of polls, support for California’s death penalty has risen — and support for an initiative to repeal it has plummeted – since the mass killings at a theater in Colorado.

A survey by the California Business Roundtable and the Pepperdine School of Public Policy, released on July 19, found that 45.5 percent of the respondents favored Proposition 34 and 46.7 percent opposed it — a statistical tie, since the difference was within the poll’s margin of error. Prop. 34 on the November ballot would abolish the death penalty and replace it with life in prison without the possibility of parole.

A day after the poll came out, a gunman killed 12 people and wounded 58 at a theater in Aurora, Colo. On Aug. 5, another gunman killed six and wounded three at a Sikh temple in Oak Creek, Wis., before being shot by a police officer. The gunman, white supremacist Wade Michael Page, then took his own life.

The first Business Roundtable-Pepperdine poll after the Aurora massacre was released Aug. 2. It found 35.9 percent of respondents in favor of Prop. 34 and 55.7 percent opposed. The latest poll, released Thursday, found 38.2 percent in favor and 52.2 percent opposed. The polling organization said its sample for that survey consisted of 811 Californians, contacted between Sunday and Wednesday, who described themselves as likely voters. The margin of error was 3.4 percent.

It’s impossible to say how much the results were affected by the mass shootings or by other events, like Jared Lee Loughner’s negotiated guilty plea Aug. 7 to serve a life term for the January 2011 shootings in Tucson that killed six people and wounded 13, including Congresswoman Gabrielle Giffords. It certainly seems plausible that news of a mass murder would evoke an emotional response and support for greater punishment.

The director of the Yes-on-34 campaign isn’t buying it. Natasha Minsker called the Business Roundtable-Pepperdine polling “very unreliable” and noted that it was conducted online, in contrast to the standard method of questioning a selected group of respondents over the telephone.

It’s hard to keep tabs on the people who take part in an Internet poll, Minsker said, and this one seems particularly questionable: It showed Prop. 34 doing better in conservative San Diego County than in the liberal Bay Area. She said phone polls by her campaign organization, and private polls she’s aware of, show Prop. 34 leading, though she didn’t give precise numbers.

But the director of the Business Roundtable poll said online surveys, though relatively new, are at least as reliable as telephone polls. Chris Condon, research director for a company called M4 Strategies, said respondents are chosen carefully to reflect the demographics of California’s voting population and checked to make sure they’re who they say they are. They’re also paid a small sum as an incentive. Condon said he’s compared some past results with phone polling on the same issues and found they were pretty close. Although the online surveys obviously leave out anyone who lacks a computer, Condon said phone polls likewise omit people without land lines, and also have to rely on the pollster’s oral description of each ballot measure. Participants in the online polls, Condon said, see the measure’s title and summary and can open a link to the ballot arguments. “In a sense, we’re closer to how people vote,” he said....

Whatever the method, Mitch Zak, spokesman for the No-on-34 campaign, said the latest poll “highlights what folks have known all along: Californians strongly support the death penalty.”