Cullison graduated from Baylor University with a degree in business administration and served in the United States Marine Corps Reserve.

[13] Cullison and Speaker Glen D. Johnson Jr. filed a lawsuit to the Oklahoma Supreme Court to challenge two partial vetoes done by Governor David Walters against two pieces of legislation in 1991.

[17] In 1986, Cullison was selected by the Democratic caucus to succeed Rodger Randle as President pro tempore of the Oklahoma Senate, who was retiring, starting in 1989.

[27] He called for Nance Diamond, his opponent in the lieutenant gubernatorial primary runoff, to be prosecuted by the Oklahoma Ethics Commission for not disclosing some of her campaign contributions.

[32] On December 20, Oklahoma County District Attorney Robert H. Macy asked for the Oklahoma State Bureau of Investigation to start an investigation into stock transaction that involved Cullison, Senator Cal Hobson, former city councilor Pete White, and lobbyist Mike Williams.

[33] Governor Frank Keating asked for Cullison's nomination to the tax commission to be delayed until the inquiry was completed.

[35] A grand jury voted in 1996, to not indict Hobson, Cullison, White, and Williams for the transactions, but called for legislators and public officials to be barred from business dealings with lobbyists.

[36] Cullison served on the three-member tax commission until his resignation on August 1, 1997, and he was replaced by Jerry Johnson, a Democrat who was appointed by Keating.