he tragic massacre at Sandy Hook Elementary in Connecticut last Friday morning has reinvigorated the national debate on gun control, prompting pollsters, policymakers, and advocates on both sides of the subject to revisit the long-dormant issue. As America adjusts to a post-Newtown landscape that could permanently change the discussion about guns in this country, here are some crucial numbers to keep in mind:

270 million
Privately owned firearms in the United States

9
Guns for every 10 people in America

55 
Percentage of Republicans who had a gun in their house in 1975

50
Percentage of Republicans who had a gun in their house in 2010

45 
Percentage of Democrats who had a gun in their house in 1975

22
Percentage of Democrats who had a gun in their house in 2010

50 
Percentage of independents who had a gun in their house in 1975

30
Percentage of independents who had a gun in their house in 2010

57
Percentage of Americans who believe gun laws should be stricter

9
Percentage of Americans who believe gun laws should be less strict

More than 180,000
Americans who have signed a White House petition in the last few days asking for immediate gun control legislation

$719,596
Amount the NRA donated to political candidates in 2012

$634,146
NRA donations received by Republicans in 2012

$244 million
The NRA's total annual spending in 2010

$3 million
The total 2010 spending for the Brady Center to Prevent Gun Violence — the nation's largest pro-gun-control group 

Sources: Politico, CBS News, WhiteHouse.gov, Washington Post (2, 3), New York Times, Slate