Former Virginia Govs. Tim Kaine (left) and George Allen after a Senate debate in Richmond, Va., on Dec.. 7, 2011. Steve Helber/AP hide caption

itoggle caption Steve Helber/AP

An image from the Republican National Committee's Facebook page advertises its new "Social Victory Center" app. RNC via Facebook.com hide caption

itoggle caption RNC via Facebook.com

Fairchild's first microchip combined four transistors, six resistors and their interconnecting wires onto a single sliver of silicon, in 1960. Today's microprocessors can employ more than 1 billion transistors. Fairchild/Courtesy of the Computer History Museum hide caption

itoggle caption Fairchild/Courtesy of the Computer History Museum

Conservative talk show host Rush Limbaugh talks with guests at the White House in 2009. Limbaugh apologized March 3 to Georgetown University law student Sandra Fluke after he branded her a "slut" and "prostitute." Ron Edmonds/AP hide caption

itoggle caption Ron Edmonds/AP