We turn now to Washington for more reaction to this brazen attack. The Obama administration is sending a Marine anti-terrorism unit to bolster security in Libya. It's also taking precautions elsewhere. The stepped up security comes as the State Department mourns its losses. NPR's Michele Kelemen has that story.
MICHELE KELEMEN, BYLINE: Shock and sadness hovered over the State Department as Secretary of State Hillary Clinton spoke of the devastating losses of four foreign service personnel.
This morning, Secretary of State Hillary Clinton said this about the slain ambassador, Christopher Stevens.
SECRETARY HILLARY CLINTON: He risked his life to stop a tyrant, then gave his life trying to help build a better Libya. The world needs more Chris Stevenses.
BLOCK: Earlier this year, before Chris Stevens assumed his position as ambassador to Libya, he made a video, subtitled in Arabic, directed to the Libyan people. It was posted on the U.S. Embassy's website and on YouTube.
From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
MELISSA BLOCK, HOST:
And I'm Melissa Block.
In this hour of the program, we remember Christopher Stevens, the first sitting U.S. ambassador killed in more than 30 years. And we'll explore how the attacks in Libya and Egypt have become fodder for political debate.
Every election season Republicans and Democrats tried to rally their base and to go after undecided voters. They're increasingly using the Internet in Get Out The Vote efforts.
NPR correspondent Shankar Vedantam, who reports on social science research, joins me now to talk about how Facebook could become a potent weapon in going after the biggest untapped voting bloc in the nation. Shankar, welcome.
SHANKAR VEDANTAM, BYLINE: Hi, Melissa.
BLOCK: Who are these mystery voters, this untapped voting bloc that we mentioned?