[3] Following his father's steps, he also received a Juris Doctor degree from Tulane University Law School after completing his undergraduate at Centenary College of Louisiana.

[8] In 1962, Jack joined his House colleague, Representative Parey Branton of Shongaloo in Webster Parish, in calling for a change in the method by which Louisiana allocates its electoral votes.

[9][10] Jack's House tenure extended from the administrations of Governors Sam Houston Jones to the second term of Jimmie Davis.

During his long career in the House, Jack served alongside numerous colleagues who reached the highest point in state politics, including Taddy Aycock, Bill Dodd, C. H. "Sammy" Downs, John McKeithen, Louis J. Michot, deLesseps Story Morrison, Sr., Dave L. Pearce, and William M. Rainach, along with his Caddo colleagues Algie D. Brown, Frank Fulco, and James C.

[2] Jack lost his House seat after twenty-four years because two Republicans, Morley A. Hudson and Taylor W. O'Hearn, led the field of legislative candidates in 1964.

In addition to Jack, the other Democrat eliminated in the 1964 election was Jasper K. Smith, a lawyer from Vivian in northern Caddo Parish.

Days after President Lyndon B. Johnson signed into law the Civil Rights Act of 1964, Jack wrote a letter to the former Shreveport Journal reaffirming his own belief in segregation: "The white man and the Negro man are happy with their lot here in this area ..."[11] In 1966, two years after his legislative service lapsed, Jack ran unsuccessfully for the Louisiana Public Service Commission, a utility regulatory agency, in an attempt to win the seat held by the appointed John S. Hunt, II, of Monroe, a nephew of Governors Huey Pierce Long, Sr., and Earl Kemp Long.