Well there it is in their own words

Address Gun Violence in Cities: Obama and Biden would repeal the Tiahrt Amendment, which restricts the ability of local law enforcement to access important gun trace information, and give police officers across the nation the tools they need to solve gun crimes and fight the illegal arms trade. Obama and Biden also favor commonsense measures that respect the Second Amendment rights of gun owners, while keeping guns away from children and from criminals. They support closing the gun show loophole and making guns in this country childproof. They also support making the expired federal Assault Weapons Ban permanent.