Watch Live: Obama Addresses Drones, Gitmo

I don't remember worrying about tornadoes as a little girl growing up in Oklahoma, but they were a real threat: In May 1950, the National Weather Service recorded an F-4 about an hour and a half south of Tulsa that killed five people and injured more than 30.

Wednesday kicks off a two-day virtual "March for Innovation" on immigration reform, when supporters are asked to rally lawmakers via social media instead of on the streets of the nation's capital.

Tech giant Apple has avoided paying billions of dollars in taxes to the U.S. or any country by using a complex web of Irish subsidiaries. But Apple is not alone, and none of the practices are illegal. Margaret Warner talks to Charles Duhigg of The New York Times for more on corporate tax loopholes.

A Senate Finance Committee hearing on the targeting of conservative groups by the Internal Revenue Service turned its focus to former IRS commissioner Douglas Shulman, who led the agency until last fall. Judy Woodruff has more, including testimony from his successor Steven Miller and the Treasury Department inspector general.

A Senate panel says Apple Inc. is avoiding billions of dollars in U.S. taxes by shifting profits to foreign affiliates. Watch Apple CEO Tim Cook as he testifies before the panel on the company's tax strategy.

A massive tornado ravaged a suburb of Oklahoma City on Monday, leveling buildings, killing at least 51 people, and temporarily brushing aside a trio of brewing political storms that had been the focus of official Washington in recent weeks.

Myanmar President Thein Sein becomes the first leader of Myanmar to visit the White House in 47 years on Monday. Some advocacy groups are concerned that the Obama administration is rewarding Myanmar before Thein Sein has followed through on all of his promises for reforms.

At this point, there appears to be more heat than light when it comes to discussion of the Internal Revenue Service's singling out of conservative groups for extra scrutiny when applying for tax-exempt status.