Wallace challenged sitting President Lyndon B. Johnson in the 1964 Democratic presidential primaries, but Johnson prevailed in the race. In the 1968 presidential election, Wallace ran a third party campaign in an attempt to force a contingent election in the United States House of Representatives, thereby enhancing the political clout of segregationist Southern leaders. Wallace won five Southern states but failed to force a contingent election. As of 2020[update] he remains the most recent third-party candidate to receive pledged electoral college votes from any state. Wallace won election to another term as Governor of Alabama in 1970 and ran in the 1972 Democratic presidential primaries, once again campaigning for segregation. His campaign effectively ended when he was shot in Maryland by Arthur Bremer, and Wallace remained paralyzed below the waist for the rest of his life. Bremer was sentenced to 63 years in prison for the shooting, which was later reduced to 53 years following an appeal; he served 35 years of the reduced sentence and was paroled in 2007.