In the year since the Newtown, Conn. school shootings, President Obama and other gun control advocates have repeatedly pointed to polls showing that substantial majorities support expanded background checks on private gun sales. As Obama put it in March, “How often do 90 percent of Americans agree on anything?”

Obama was right – some surveys conducted soon after the Newtown tragedy did find 90 percent support for expanded background checks. But a review of polling over the past year provides a more complicated picture of public opinion about guns and gun control, which partly helps explain why a bipartisan background checks bill died in the Senate last April.

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