President Obama announced new executive actions to curb gun violence including expanding background checks and mental health screenings. North Korea claimed this week to have successfully tested a hydrogen bomb. On the 2016 campaign trail, Republican frontrunner Donald Trump is questioning his GOP rival Ted Cruz's eligibility to run because he was born in Canada.

President Obama announced new executive orders on gun control including requiring all firearms dealers to obtain licenses, new funding for mental health treatment and exploring ways to increase gun safety. During the president’s announcement, he invoked the deaths of 20 students and six educators at a Newtown, Connecticut school in 2012 as reason for action.

The FBI is investigating the mass shooting in San Bernarndino, California, that left 14 people dead as "an act of terror" after one of the suspects declared her allegiance to ISIS in an online post. NBC News' Pete Williams updates us on where the investigation stands. Plus, the shooting has revived political conversations about enhancing gun laws in America.

Hillary Clinton asserted this week that her team is not digging up information on Vice President Joe Biden if he were to run, but Anne Gearan of The Washington Post believes Clinton’s team is not sitting idly by waiting for Biden's decision.

After a gunman opened fire at a community college in Oregon killing nine people, President Obama made an impassioned appeal for stronger gun control policy. Despite Obama's plea, Alexis Simendinger of Real Clear Politics says there seems to be no appetite to bring up new gun legislation on Capitol Hill and if any change occurs it’ll be a project for the next president.

A shocking, televised murder in Virginia has provoked a wide array of questions about the shooter and how horrific images go viral online. Gwen Ifill speaks with Deborah Potter of NewsLab, Lance Ulanoff, chief correspondent and editor-at-large at Mashable, and Barry Rosenfeld of Fordham University.

A horrific mass shooting at a movie theatre near Denver, Colorado. The campaigns talk about tax history and economic policy as attack ads from both campaigns intensify. And the fighting in Syria spreads to Damascus as the rebels achieve new victories. Joining Gwen: Pierre Thomas, ABC News; Karen Tumulty, The Washington Post; Jeff Zeleny, The New York Times; Doyle McManus, Los Angeles Times.

Gun control debate is again at the forefront after a tragic Conn. school shooting. Amidst continued fiscal cliff talks, Susan Rice chooses not to pursue the Secretary of State nomination. Plus, the U.S. recognizes the Syrian opposition. Joining Gwen: Reid Wilson, National Journal Hotline; Martha Raddatz, ABC News; David Sanger, New York Times; John Dickerson, Slate Magazine and CBS News.

Obama's second-term cabinet continues to take shape with three new members nominated to his national security and economic teams. TheWhite House considers legislation to curb gun violence. Obama and Karzai agree to speed up Afghan military transition. Joining Gwen: Alexis Simendinger, Real Clear Politics; James Kitfield, National Journal; David Wessel, Wall Street Journal; Christi Parsons, Tribune

We look at the countdown to automatic spending cuts on March 1, China's alleged hacking of U.S. businesses, and gun violence in America as part of the PBS special programming 'After Newtown.' Joining Gwen: John Harwood, CNBC and New York Times; David Sanger, New York Times; Molly Ball, The Atlantic; Sari Horwitz, Washington Post.