Humberto Manzano Jr. moves a pallet of goods at an Amazon.com fulfillment center in Phoenix in 2010. Amazon has endorsed a bill making its way through the Senate that would require more online retailers to collect sales tax. Ross D. Franklin/AP hide caption

itoggle caption Ross D. Franklin/AP

President Obama urged Congress to take action on measures to protect children from gun violence while speaking in the East Room of the White House last week. Standing with Obama are Vice President Joe Biden and, according to the White House, law enforcement officials, victims of gun violence and others, whom the White House did not want to name. Susan Walsh/AP hide caption

itoggle caption Susan Walsh/AP