On Tuesday's broadcast of "CNN Primetime," Sen. Elizabeth Warren (D-MA) refused to say whether or not New Mexico Gov. Michelle Lujan Grisham (D) can use a public health emergency declaration to unilaterally change the state's gun laws, but said "mayors and our governors have the hardest job in the world right now when it comes to gun violence" because "an extremist United States Supreme Court" has prevented them from enacting good policies like completely banning carrying guns.