A native of East Baton Rouge Parish, Simpson graduated from Baker High School in 1971 and holds both bachelor’s and master’s degrees in education from LSU in Baton Rouge. He is a nonpracticing Certified Public Accountant. Simpson and his wife, the former Allison Windham (born 1954), have four children. They still reside in Baker and are affiliated with the non-denominational Christian church, the Bethany World Prayer Center. He is a golfer and a runner.
In 2001, Simpson succeeded the retiring Tom Ed McHugh as Mayor-President by defeating Melvin "Kip" Holden, an African American Democrat in the 2000 general election. Holden then unseated Simpson in 2004 and was easily reelected in the nonpartisan blanket primary in 2008. Simpson did not seek a comeback; instead Holden was opposed by two other Republican candidates, Metro council member Wayne Carter and the former Louisiana legislative auditor and Louisiana State University professor Dan Kyle.
Simpson was elected mayor of Baker in 1992 over the Democrat Frank C. Blackburn. In the primary, he led with 1,997 (32.4 percent) to 1,147 (31.1 percent). Two other Democratic candidates held the remaining nearly 37 percent of the vote. In the general election, Simpson defeated Blackburn, 2,100 (54.4 percent) to 1,762 (45.6 percent). In 1996, Simpson defeated a fellow Republican, Lamon L. Moody, Jr., 2,022 (82.6 percent) to 425 (17.4 percent). Simpson was unopposed for a third term as mayor in March 2000, but he served less than a year thereafter upon winning election as East Baton Rouge Mayor-President. In the seeking the greater position, Simpson claimed that he had saved the city of Baker millions through careful budgeting and financial management.
Six candidates, four Republicans and two Democrats, contested the October 2000 primary for Mayor-President. Democrat Holden led with 34,780 (31.2 percent), and Simpson trailed with 27,928 (25.1 percent). Republican Rolfe H. McCollister finished third with 21,850 votes (19.6 percent). Three other candidates held the remaining 24 percent. One of those unsuccessful candidates was Fred Columbus Dent, Jr. (1937–2010), a former Green Beret and the son of the late Louisiana Register of State Lands Lucille May Grace. He drew 6 percent of the vote. Simpson then defeated Holden in the November 7 general with 93,952 (56.9 percent) to 71,087 (43.1 percent). Simpson outpolled Republican presidential nominee George W. Bush in East Baton Rouge Parish, who received 89,128 votes (52.7 percent).
Mayor Simpson was elected in 2002 as president of the Louisiana Municipal Association, having succeeded Ned Randolph of Alexandria in Rapides Parish. He was also president of the Louisiana Conference of Mayors. Early in 2004, he unveiled a 10-year plan endorsed by the U.S. Conference of Mayors with the goal of ending chronic homelessness in Baton Rouge. Simpson endorsed the Samaritan Initiative, an effort to tap into community-wide resources to move the homeless from the streets and temporary shelters into houses.
Faced with crime problems, Simpson was active in the organization of a task force to catch suspected serial killer Derrick Todd Lee. Caught after ten months as a fugitive in Atlanta, Georgia, in 2003, Lee waived extradition and was returned to Baton Rouge. The case caused Baton Rouge police to re-examine cases previously excluded because there were no DNA connections.
By the time he sought reelection as Mayor-President, Simpson's political fortunes had plummeted. In addition to Holden, five other opponents filed for the office. Holden led in the primary with 39,470 (35.1 percent) to Simpson’s 38,206 (33.9 percent). In the general election, Holden unseated Simpson, 94,802 (53.9 percent) to 81,142 (46.1 percent). Simpson trailed the second President Bush by 18,801 ballots in East Baton Rouge Parish.
Simpson began his career as a teacher and dean of students at the Louisiana School for the Visually Impaired in Baton Rouge. On November 30, 2009, he returned to that institution as the interim director, pending a national search for a permanent director. Simpson is certified as a school principal, supervisor of student teachers, and instructor of the blind and partially sighted. Prior to his latest appointment, Simpson had been chief operations officer at JTS Realty Services. Simpson was hired at JTS by developer Tommy Spinosa.