Newsletter: Essential Politics: The shadow of terrorism darkens the campaign

The killing of 14 people in San Bernardino this week, along with the growing evidence that the two assailants had at least ideological connections with radical Islamist militant groups overseas, is the sort of sudden, unpredicted event that political campaign planners dread.

How will the event change the way voters look at the candidates? Who will benefit? How can a candidate take political advantage of the changed circumstances without appearing to politicize a tragedy?

Good afternoon, I'm David Lauter, Washington bureau chief. Welcome to the Friday edition of Essential Politics, in which we examine the major developments of the past week and highlight some stories that go beyond the immediate headlines to provide insight into the campaign.

Questions about how to respond to the San Bernardino shootings inevitably ricocheted around campaign offices in the last couple of days. Some candidates were quick to jump on the issue, others treated it gingerly.

As Noah Bierman and Evan Halper noted, Democrats and Republicans framed the issue entirely differently. Democrats sought to turn the debate toward gun control, while Republicans discussed it in terms of international terrorism.

New Jersey Gov. Chris Christie, who has been trying to mount a political comeback by portraying himself as tough enough to handle the Islamic State militants, was the Republican candidate most intent on discussing the attack.

"From the time I began to watch the events unfold last night, I [was] convinced that it was a terrorist attack," he declared in a speech Thursday. “The president continues to wring his hands and say, ‘We’ll see.’ … But those folks dressed in tactical gear with semi-automatic weapons came there to do something.”

Sen. Ted Cruz of Texas also emphasized the attack in his speech Thursday to a forum sponsored by the Republican Jewish Coalition -- a group funded primarily by Las Vegas billionaire Sheldon Adelson. By contrast, Sen. Marco Rubio of Florida barely discussed it.

On the Democratic side, the greater public focus on terrorism could be problematic since voters in the past have often seen Republicans as stronger in times of trouble. The party's front-runner, Hillary Clinton, has tried to counter that by emphasizing her experience and steadiness in a crisis.

While those developments ripple through the campaign, expect to see more volatility in public opinion polls. But take them with a grain of salt. As Doyle McManus noted in his column, it's still early, and early horse race polls don’t mean very much.

As George Washington University political scientist John Sides told McManus, the predictive power of horse race polls is low until “roughly a month before the Iowa caucuses." So you can safely discount much of the gyrations in the numbers until the new year.

Seen elsewhere:

Speaking of polls, Harry Enten at the 538 website had an excellent deep dive on one of the big questions vexing polling experts so far in this campaign: Why does Donald Trump consistently do better in online polls than in surveys that use live interviewers?

Ryan Lizza in the New Yorker looked at the fight between Rubio and Cruz and how campaigns reinforce the timidity of legislators.

And don't miss this gem of an interview with Christie that Jeffrey Goldberg did for the Atlantic. Come for the foreign policy substance, stay for the great insults.

That wraps up this week. On Monday, my colleague Christina Bellantoni will be back with the daily newsletter. Until then, keep track of all the developments in the 2016 campaign with our Trail Guide, at our politics page and on Twitter at @latimespolitics.

Send your comments, suggestions and news tips to politics@latimes.com.