Over that span, the percentage of households with guns dropped from more than half in 1977 to just more than 30 percent in 2010.
Gallup, meanwhile, shows a similar drop -- though it found 41 percent of households still had guns as of 2010.
But then something happened in 2011. Gun ownership spiked to its highest level since 1994 -- 47 percent.
The people who suddenly had more guns? Not the white males, the Southerners, and the Republicans most associated with guns. Instead they were mostly Democrats....
... and people in every region but the South.
We don't yet have the 2012 data to see whether the trend continued or the poll was an outlier. (For what it's worth, Gallup suggests more people copped to having guns in 2011 because the country as a whole was more comfortable with guns, but that doesn't explain why that wasn't also the case in preceding years, when opposition to new gun laws was about as high).
Either way, the increase in 2011 was the highest on record, and gun ownership levels in the East, the Midwest, among women and among Democrats were all higher than they had been in at least two decades.
If anything, these charts should serve to remind everyone that guns are not a red and blue issue. And gun owners in America are actually pretty diverse -- and quite possibly more diverse than they have been in recent decades.
Several pro-gun Democrats have started to nudge the country more toward a conversation about gun control, but voting for a specific measure is another matter entirely.
And it's not just Middle America where these Democrats have to be concerned about losing votes.