WASHINGTON, Jan. 28 (UPI) -- Just four days before the Iowa caucuses, Bernie Sanders has put his name on a bill allowing victims of gun violence to sue gun manufacturers and dealers.
Vermont Senator Bernie Sanders became a co-sponsor on Thursday.
Sanders' new position is in conflict with a bill he voted for in 2005 that granted gun manufacturers and gun sellers immunity from prosecution -- a vote that rival Democratic candidate Hillary Clinton and other critics have been using against him as the Democratic primary campaign has tightened, with Sanders now leading in New Hampshire and within the margin of error in Iowa in the most recent polls.
In a July 2015 appearance on CNN, Sanders said that allowing people to sue gun makers for damages related to crimes involving guns would be like allowing people to sue the makers of hammers after a hammer is used in a crime. He's also said he didn't want to hurt small gun-sellers in Vermont, who could be put out of business if a gun they sold was used in a crime.
Clinton, who voted against the 2005 bill as a New York senator, has said if she's elected president she would "stand up to the gun lobby, not protect it."
During the first Democratic debate in October, CNN host Anderson Cooper raised the issue and asked Clinton if Sanders is "tough enough on guns."
"No, not at all" she replied flatly. "Sen. Sanders did vote five times against the Brady [gun control] Bill. .. He also did vote for the  immunity provision. I voted against it. I was in the Senate at the same time. It wasn't that complicated to me, it was pretty straight forward."
The new bill is unlikely to pass a Republican-controlled Congress, but some say it absolves Sanders of his earlier sin, at least in part, and puts him in better stead with Democratic voters who are staunch supporters of gun control.
"This is the least he can do," Dan Gross, president of the Brady Campaign to Prevent Gun Violence, said. His organization has endorsed Clinton for president.
"The difference between Clinton and Sanders is that she didn't wait until the campaign to champion gun violence prevention," he added.
Sanders has said he is "disappointed" by recent criticism that has come from Clinton's camp, but noted that he has presented a clear vision of what he intends to do as president -- something he believes the former Secretary of State has not yet done.
"Secretary Clinton is spending a lot of time saying what she's not going to do. Bernie is spending his time telling Iowa voters and people across the country where he intends to lead the nation as president," Jeff Weaver, Sanders' campaign manager, said. "Bernie Sanders will build on the achievements President Obama has made and build for the future."
Clinton and Sanders have both been criticized for their TV "attack" ads in the closing days of the primary campaigns in Iowa, where caucuses will be held on Monday, Feb. 1, and New Hampshire, which will hold the first-in-the-nation primary on Tuesday, Feb. 9.
"Sen. Sanders has said repeatedly he doesn't do that, he doesn't engage in negative attacks, and I take him at his word," Clinton said in an interview with MSNBC's Rachel Maddow earlier this month. "We don't do that. ... We engage on substantive differences, and we have some."
Also Thursday, Sanders announced that he has been given a clean bill of health by his physician.
Sanders, 74, posted the letter from his doctor, Rear Adm. Brian P. Monahan, on his campaign website. It summarizes recent health checkups, Sanders' medical history and other pertinent medical issues.
"You are in overall very good health and active in your professional work, and recreational lifestyle without limitation," it states.