This is a sampling from Bay Area News Group's Political Blotter blog. Read more and post comments at www.ibabuzz.com/politics.

Feb. 19

A federal judge on Wednesday refused to issue a preliminary injunction blocking San Francisco's new ban on possession of ammunition magazines that hold more than 10 rounds, and so the law will take effect as planned on April 7.

The state's assault weapon ban has forbidden such magazines' manufacture, sale or transfer since 2000, but let people who owned them before then keep them. San Francisco supervisors on Oct. 29 unanimously approved a ban that will require owners to get rid of them -- turn them over to police, remove them from the city, or transfer them to a licensed firearms dealer -- within 90 days, no matter when they were bought.

The San Francisco Veteran Police Officers Association, backed and represented by the National Rifle Association, sued in November to prevent the new law from taking effect. But U.S. District Judge William Alsup issued a 12-page ruling Wednesday that concluded immediate enforcement is in the public interest.

"In assessing the balance of equities, those rare occasions must be weighed against the more frequent and documented occasions when a mass murderer with a gun holding eleven or more rounds empties the magazine and slaughters innocents," Alsup wrote. "One critical difference is that whereas the civilian defender rarely will exhaust the up-to-ten magazine, the mass murderer has every intention of firing every round possible and will exhaust the largest magazine available to him. On balance, more innocent lives will be saved by limiting the capacity of magazines than by allowing the previous regime of no limitation to continue."

The judge also noted that 86 percent of mass shootings in the past 30 years involved at least one magazine that could hold more than 10 rounds, and more people are injured and killed per mass shooting with such magazines than without. "San Francisco's interest in preventing another Sandy Hook tragedy constitutes a 'critical public interest.'"

A spokesman for Chuck Michel, the NRA's West Coast counsel, said the plaintiffs will appeal Alsup's ruling.

City Attorney Dennis Herrera issued a statement applauding the decision.

"The U.S. Supreme Court has been very clear that state and local governments are constitutionally entitled to enact reasonable firearms regulations, and that Second Amendment rights aren't unlimited," he said. "Unfortunately, the NRA is pushing a radical litigation strategy that goes far beyond what's reasonable. I'm grateful to the district court for drawing that distinction in persuasive terms."

Feb. 21

Silicon Valley's House members want an update on the Department of Homeland Security's investigation of the sniper attack on PG&E's Metcalf power substation last April.

Reps. Zoe Lofgren, D-San Jose; Anna Eshoo, D-Palo Alto; and Mike Honda, D-San Jose, wrote a letter Thursday to Homeland Security Secretary Jeh Johnson.

"Although the damage from the Metcalf incident was largely contained, the potential for a catastrophic attack impacting both our electric grid and communications infrastructure is evident," the lawmakers wrote. "As we understand it, rolling blackouts throughout our region were narrowly averted. The Metcalf attack, while sophisticated, was relatively small. A larger attack is not difficult to imagine and the effects could be crippling."

Somebody fired rifle rounds last April to take out 17 transformers and 6 circuit breakers, causing $15.4 million in damage at the facility near Coyote Ranch Road in South San Jose. Nobody was hurt and nobody lost power, but circumstances suggest it was a planned attack.

Given the Bay Area's high concentration of Fortune 500 companies, patent generation and economic productivity, a successful attack on the area's power grid "would impact not only our region but our country as a whole," they wrote.

The lawmakers asked Johnson to respond by March 14 with a summary of his department's work on the incident, including the initial emergency response; work since the incident on improving protection of critical infrastructure, emergency mitigation and coordination with other agencies; recommendations for more improvements; and guidance on whether any congressional action is needed.