Vice President Joe Biden on Tuesday, seeking to revive efforts to pass gun-reform legislation in Congress, warned lawmakers opposed to reform that Americans aren't on their side. "The country has changed" since the deadly shootings at Sandy Hook Elementary School in Newtown, Conn., Biden said during remarks delivered on Tuesday afternoon in the White House's South Court auditorium. Lawmakers "will pay a price—a political price ... for not getting engaged and dealing with gun safety." Two months after the Senate failed to support the expansion of background checks for gun purchasers despite intense pressure from the administration, victims rights groups...