Sen. Chuck Schumer, D-N.Y., left, has received backing from gun control supporters while gun rights backers gave big to Sen. Orrin Hatch, R-Utah.

When National Rifle Association CEO Wayne LaPierre faces the members of the Senate Judiciary Committee this morning in the first congressional hearing about gun control since the last month's massacre at a Connecticut elementary school, he'll be facing lawmakers who have strong feelings about his organization. Some of them have reason to feel grateful for the NRA's financial support; others have reason to resent its opposition.

Other witnesses scheduled to testify include Mark Kelly, the retired astronaut who is married to former Rep. Gabrielle Giffords, an Arizona Democrat who suffered severe brain injuries in an assassination attempt during a congressional town hall meeting. Kelly and Giffords just established a super PAC to push for stronger gun control laws, Americans for Responsible Solutions. 

MORE: For data on the gun debate, see the Sunlight Foundation's resource page.

An analysis by the Sunlight Foundation of campaign records show that the NRA and other gun rights organizations have played a role in the campaigns of a majority of the Judiciary Committee's 18 members Most of the members of the Senate Judiciary Committee convening this morning to hear witnesses talk about gun violence have either enjoyed the support of the National Rifle Association (NRA) and other gun rights groups come election time or suffered their opposition.

Eleven out of the 18 members of the committee have enjoyed the support of gun rights groups, whether through direct contributions or independent expenditures in favor of their campaigns, according to Sunlight's Influence Explorer. All eight of the committee's Republicans have gotten support and all enjoy "A" ratings by the NRA.  Several members who won tough races last year got donations in the six-figure range from gun rights backers: Sunlight's Influence Explorer shows that Sen. Ted Cruz, R-Texas, got financial support from members of Safari Club International and the Gun Owners of America. The NRA spent more than $57,000 trying to get its members out to vote for him. Sen. Orrin Hatch, a veteran Utah Republican who has chaired the Judiciary Committee and faced perhaps the toughest reelection campaign of his career last year, benefitted from more than $97,000 in independent expenditures by the NRA. 

Three of the Democrats have been hit by negative independent expenditures from the NRA–Sens. Dianne Feinstein, D-Calif.,  Al Franken, D- Minn., and Christopher Coons, D-Del. Feinstein, who has also known gun trauma — as a member of San Francisco's city council, she discovered the body of Mayor George Moscone after another city council member shot him — just introduced legislation to ban assault rifles. 

Gun control groups such as the Brady Campaign to Prevent Gun Violence have also supported lawmakers on the committee, but at much lower amounts. The groups did not make independent expenditures against anly of the lawmakers.

Other witnesses at the Judiciary Committee hearing include David Kopel, a law professor at Denver University and research director at the libertarian Independence Institute and Gayle Trotter, a senior fellow with the Independent Women's Forum, a conservative group, both of whom are expected to be hostile to new laws. James Johnson, chief of police for the City of Baltimore, has spoken out in favor of banning high capacity magazines.

Feinstein has criticized the witness list for being skewed toward gun interests and has said she will hold her own hearing on her proposed assault weapon ban. Judiciary Committee Chairman Patrick Leahy, a Vermont Democrat, has drawn no support or opposition from gun groups. His home state, Vermont, has no permitting requirements for gun owners. Leahy's staff described him to USA TODAY as a gun owner, who, like many of his constituents, enjoys sport shooting.