Walker again resigned his commission in 1961 after being publicly and formally admonished by the Joint Chiefs of Staff for allegedly referring to Eleanor Roosevelt and Harry S. Truman as "pink" in print and for violating the Hatch Act of 1939 by attempting to influence the votes of his troops.

In early 1962, Walker campaigned to become governor of Texas and lost the Democratic primary election to the eventual winner, John Connally.

Walker reported that he was the target of an assassination attempt at his home on April 10, 1963, but escaped serious injury when a bullet fired from outside hit a window frame and fragmented.

After its investigation into the assassination of John F. Kennedy, the Warren Commission concluded that Walker's assailant had been Lee Harvey Oswald.

[2] Walker's training was in artillery, but in World War II he commanded a sub-unit of the Canadian-American First Special Service Force.

Their first combat actions began in December 1943, and after battling through the Winter Line, the force was withdrawn for redeployment to the Anzio beachhead in early 1944.

In 1957, he implemented an order by President Dwight D. Eisenhower to quell civil disturbances related to the desegregation of Little Rock's Central High School.

Although he obeyed orders and successfully integrated Little Rock High School, he began listening to segregationist preacher Billy James Hargis and oil tycoon H. L. Hunt, whose anti-communist radio program Life Line was supported by conservative activist and publisher Dan Smoot.

He began promoting his "Pro-Blue" indoctrination program for troops, which included a reading list of materials by Hargis and the John Birch Society.

"[8] He later wrote that the Pro-Blue program was based upon his experiences in Korea, where he saw "hastily mobilized and deployed soldiers 'bug out' in the face of Communist units with inferior equipment and often smaller numbers.

Walker's home base was Dallas, Texas, where he received considerable assistance from oil billionaire, publisher and radio host H. L. Hunt.

Other contenders were Governor Price Daniel, Highway Commissioner Marshall Formby of Plainview, Attorney General of Texas Will Wilson, and Houston lawyer Don Yarborough, the favorite of liberals and organized labor.

Because of disfranchisement of minorities in Texas since the beginning of the century, Democratic Party primaries were the only strongly competitive political contests in the state at that time.

[15][16] Though Walker had obeyed orders during the desegregation of Central High School in Little Rock, he acted privately in organizing protests in September 1962 against the enrollment of James Meredith, an African-American veteran, at the all-white University of Mississippi.

Rally to the cause of freedom in righteous indignation, violent vocal protest, and bitter silence under the flag of Mississippi at the use of Federal troops.

He was temporarily detained in a mental institution on orders from Attorney General Robert F. Kennedy, who demanded that Walker receive a 90-day psychiatric examination.

[19] The attorney general's decision was challenged by noted psychiatrist Thomas Szasz, who insisted that psychiatry must never become used for political rivalry.

The American Civil Liberties Union joined Szasz in a protest against the attorney general, completing this coalition of liberal and conservative leaders.

[22] In February 1963, Walker joined Billy James Hargis on an anticommunist tour named "Operation Midnight Ride.

"[23] In a March 5 speech, Walker called on the American military to "liquidate the [communist] scourge that has descended upon the island of Cuba.

"[28] On April 10, 1963, as Walker was sitting at a desk in his dining room, a bullet struck the wooden frame of his dining-room window.

[32] A note that Oswald left for Marina on the night of the attempt with instructions for her should he not return was not found until ten days after the assassination.

Walker organized an October 24, 1963, UN Day attack on Adlai Stevenson, American ambassador to the United Nations, in Dallas.

[38] The verbal attacks on Stevenson were traced to plans organized by Walker and his devotees in the John Birch Society, according to the November issue of the magazine Texas Observer.

On November 22, a black-bordered advertisement ran in the Dallas Morning News and "Wanted for Treason: JFK" handbills appeared on the streets.

The Associated Press reported that Walker had "led a charge of students against federal marshals" and that he had "assumed command of the crowd.

[50] Walker, a heavy smoker, died of lung cancer at his home in Dallas on Halloween 1993, ten days before his 84th birthday.