As member of the U.S. Senate, Robert Kelly long regarded the growing number of mutants as a threat to national security. To cope with this supposed danger, he promoted legislation such as the Mutant Registration Act, requiring those with powers of genetic origin to disclose their abilities to the government. This proposal prompted the second Brotherhood of Evil Mutants to attempt to assassinate Kelly in Washington, D.C. The Brotherhood did not succeed, thanks to the intervention of the X-Men.
The failed assassination attempt fueled the Senator's resolve to pass the Registration Act. He cultivated a partnership with industrialist Sebastian Shaw, who built mutant-hunting Sentinels and supported Kelly's plans. Unbeknownst to the Senator, Shaw was a mutant and the Black King of the Hellfire Club. Following one of his meetings with Shaw in New York, the Senator's limousine was demolished by debris from a fight involving the X-Men. Kelly survived -- but his wife, Sharon, died in the wreckage. Kelly's grief strengthened his position that mutants were too dangerous to be allowed to run rampant, and he ordered the production of more Sentinels.
Kelly supported "Operation: Zero Tolerance" until he realized the android known as Bastion, programmed to exterminate mutants, was using the program to convert innocent humans into Sentinels and trampling on the rights of U.S. citizens. When he withdrew his support, the Senator became one of the Sentinels' targets. To save his life, he called on the X-Men and wielded his political influence to enlist the worldwide intelligence and peacekeeping organization S.H.I.E.L.D. to shut down Bastion. His political views unaffected by the experience, Kelly declared his candidacy for president on an anti-mutant platform.
To ensure his safety against another assassination attempt by the Brotherhood, the Senator accepted Professor Charles Xavier's offer of assistance and added the X-Men's Cable to his personal security team. As the evil mutant Post maneuvered toward Kelly at a rally in Boston, former Brotherhood member Pyro used the final manifestation of his powers to kill the assassin and save Kelly's life. Pyro's selfless act finally prompted the Senator to re-evaluate his stance on mutants.
Ironically, an anti-mutant activist believed the Senator betrayed his human brothers by toning down his rhetoric and assassinated him.
