( CNN ) -- The drive for a tough federal gun control law has hit a political roadblock . But that 's not silencing Joe Biden and Mike Bloomberg . The loquacious vice president and the outspoken New York mayor on Thursday touted the `` importance of passing common sense legislation to reduce gun violence , '' including the need for a stiff background check system for all gun sales . They joined families of those killed last December in the shooting massacre in Newtown , Connecticut , to push for new rules . They spoke at New York City Hall as prospects for a ban on semi-automatic weapons styled after military assault weapons appeared to founder . Bloomberg cited public opinion polls showing wide support for background checks , saying `` there 's no real debate '' among Americans about this issue . He said nationwide background checks on all gun sales would save lives , and that the only question `` is if Congress has the courage to do the right thing . '' A national requirement for background checks on all gun sales is needed because guns purchased in states with `` weak gun laws '' end up in states with stricter requirements , Bloomberg said . `` We remain optimistic that Congress will take action this spring , '' he said . `` There is no question that if this becomes law , it will keep guns out of the hands of people who should not have them . It will reduce violent crime . It will save lives . We know that 's true , because in states that already require background checks on private sales , the rate of women murdered by an intimate partner armed with a gun is 38 % lower than in states that do n't have such background checks . '' The ban proposal , categorically opposed by the National Rifle Association , would get fewer than 40 votes , Senate Majority Leader Harry Reid said Tuesday , far below the threshold needed to defeat a filibuster or pass the Senate . Instead , the ban could be offered as an amendment to the gun legislation on the Senate floor in order to get a vote on it , Reid said . Biden , who lauded Bloomberg 's `` immense '' and `` committed '' gun control work , criticized those who say the proposals would violate rights . `` Tell me how it violates anyone 's constitutional rights to limit ( ammunition clips ) to 10 rounds , '' Biden said . `` Think about Newtown . ... Think about how many children and teachers may be alive today had ( the shooter ) had to reload ( more often than ) he did . '' He worked to raise the spirits of people discouraged by the power of the gun lobby . `` I was told in 1992 , when I introduced many of these reforms , that there was no way , you never beat the gun lobby , it 's not possible . Well , in 1994 , we did . In 1994 , reason prevailed , and we passed the assault weapons ban , a limitation on the size of magazines , and a number of other measures , including expanding the so-called Brady Bill and background checks . '' Many reforms have since expired . But , he said , `` One thing I want to lay to rest at the outset : They worked . They all had a positive impact on public safety . '' Biden said that the Sandy Hook Elementary School shooting in Newtown was conducted with `` a weapon of war , and that weapon of war has no place on American streets . '' The shooter , Adam Lanza , gunned down 20 children and six adult staff members with a Bushmaster AR-15 rifle . `` Taking it off American streets has no impact on one 's constitutional right to own a weapon , '' Biden said . He also noted that conservative Supreme Court Justice Antonin Scalia `` acknowledged that government has a right to limit certain weapons from being able to be possessed by American citizens . '' He expressed his admiration for the Newtown families and said their presence has helped move legislation through the Senate Judiciary Committee and gives such gun control reform a `` fighting chance . '' `` It takes an enormous amount of courage to be here , '' Biden said to the families . `` And you say , well , what 's the courage ? Having lost a child , I understand that every time you show up at something that ranges from a memorial service , or to talk about the circumstances in which your child was lost , it comes back to you in a flash , as if they got that phone call yesterday . And I told you before , I do n't know how you do it , but you do it . You do it . '' ( Biden 's first wife and the couple 's 1-year-old daughter were killed in a car accident in 1972 . ) Biden argued against those who say assault weapons and high-capacity magazines ca n't be banned . He said gun-trafficking legislation will give police power `` to be able to deal more rationally with straw sales , those sales where people go in , buy multiple guns , and then sell them to the bad guys . '' He said the more police are on the streets , the better . The proposed reforms , Biden said , `` will not solve every problem . It will not end every gun death . But it will substantially reduce it . And it matters . '' CNN 's Jason Hanna contributed to this report .
Bloomberg cites the need for background checks . Comment: