Guillory's Senate district was previously briefly represented by the Democrat Don Cravins, Jr. It encompasses most of St. Landry Parish and a northern part of adjacent Lafayette Parish. Guillory defeated Patricia "Pat" Arceneaux Cravins (born 1947) of Arnaudville, the mother of Don Cravins, Jr., in the special state Senate runoff election held on May 2, 2009, 7,906 votes (62.5 percent) to 4,746 (37.5 percent).
Guillory previously served from 2006 to 2009 as state representative for District 40. In that position he had also succeeded the Democrat Don Cravins, Jr., whose father, Don, Sr., was also a former state senator and a mayor of Opelousas.
Guillory was reared in a divorced family in St. Landry Parish."My parents lived seven miles from each other on the same road. They were both always part of my life, but they could never live together. They were opposites."
His Roman Catholic father, Ozema Ledee (died c. 2009), was an entrepreneur and an adventurer who flew his own plane, a rarity for a black man in the 1950s. He was also a bootlegger. Guillory's mother, who was still living in 2013 at the age of 104, was a strict Baptist who forbade alcohol and cursing in her home. She worked as a teacher and school principal.
Guillory had aspirations of becoming a physician, but switched to studying law. In 1961, he enrolled in historically black Southern University in Baton Rouge. As the editor of the university paper, The Digest, he wrote an editorial in which he referred to U.S. Senator Allen J. Ellender, a Democrat from Houma, Louisiana, as a "lunatic", for which Guillory was expelled from Southern. He subsequently joined the Navy, obtained his Bachelor of Arts at another historically black institution, Norfolk State University, Virginia, and obtained his Juris doctor from Rutgers School of Law in Newark, New Jersey. He also attended a Baptist theological seminary in New York to study for the ministry, but was never ordained. From 1985 he practiced law in his native Opelousas.
Guillory has been married and divorced four times His avocation is mountain climbing. Not only has he reached the summit of Mount Rainier in Washington State and Denali in Alaska, but he also has climbed his "namesake" Mount Elbert, the apex of the Colorado Rockies.
Up until 2007, Guillory had been a registered Republican and served on the Louisiana Republican state central committee. He became a Democrat in 2007 when he first ran for the state House in the heavily Democratic District 40. During the 2013 regular session of the Louisiana Legislature, Guillory switched his party affiliation back to Republican. Officially, Guillory's party-switch occurred on May 31, when he was presented with the Frederick Douglass Award from the @Large Society.
State Senator Karen Carter Peterson, the chair of the Louisiana Democratic Party, had indicated racism to be the reason why the Louisiana Legislature and Governor Bobby Jindal opposed the Patient Protection and Affordable Care Act, enacted in 2010 by Congress and signed into law by President Barack H. Obama. Jindal and the legislature had declined to implement in Louisiana that part of the federal act expanding eligibility for Medicaid, largely with federal funding. Guillory took exception to Carter Peterson's characterization of the opponents of the law, but his intent to switch parties had already been under consideration.
Before Guillory's switch, the last Republican of African-American ethnicity in the Louisiana Senate had served during the Reconstruction era. In accepting the award, Guillory compared himself to 19th-century abolitionist Frederick Douglass, a Republican who had supported Abraham Lincoln.
Guillory's conservative political philosophy was indicated in his pre-2007 membership in the Republican Party, according to Daily Kos, Guillory explained his 2013 party switch in a 4-minute 17-second video widely circulated in state and national media outlets, including the radio programs of Rush Limbaugh, Sean Hannity, and Moon Griffon as well as by Neil Cavuto on Fox News. The video was viewed on YouTube within the first three days by nearly 500,000. Filmed in the rear of the Senate chamber, the video calls the Democrats "the party of Jim Crow" and depicts "the party of freedom and progress" as the Republicans. Guillory called his switch "not only right for me, but for all of my brothers and sisters in the black community" as he left the Democrats for the Republicans.
Soon after re-joining the Republican Party, Guillory founded the Free at Last PAC, a political action committee dedicated to electing black conservatives to office.
Guillory spoke in a hearing about the Louisiana Science Education Act, a law concerning religion and science in public schools. Guillory argued to keep the law on the books because of an experience he had with a witch doctor—who “wore no shoes, was semi-clothed, used a lot of bones that he threw around”.
Guillory remained a member of the Louisiana Legislature's Black Delegation, a caucus—a matter clarified by Legislative Black Caucus Chair State Representative Katrina Jackson, a Democrat from Monroe. The Baton Rouge Advocate in an editorial asserted that Guillory's switch to the Republicans "favors the GOP's efforts to broaden its base".
Within days of Guillory's change of parties, Jim Shannon of KLTV-TV speculated that Guillory would become a candidate for lieutenant governor in the 2015 state elections, when Jay Dardenne stepped down to run unsuccessfully against Democrat John Bel Edwards and fellow Republican U.S. Senator David Vitter for the governorship vacated by the term-limited Bobby Jindal. In the runoff on November 21, 2015, Edwards won the election over David Vitter with 56.1% of the vote, becoming the first Democratic governor elected in the Deep South since the end of Kathleen Blanco's term in 2008.
Others in the race for lieutenant governor included a defeated 2011 candidate, Billy Nungesser, the president of Plaquemines Parish, and John Young, the Republican president of Jefferson Parish. Democratic Mayor-President Kip Holden of East Baton Rouge Parish, another African-American, also is seeking the office. The position is focused upon the promotion of tourism in Louisiana.
Guillory ran last in the October 24 four-candidate primary, having finished with 85,460 votes (7.9 percent). Holden with 360,679 votes (33.3 percent) and Nungesser, who polled 324,654 (30 percent), meet in the November 21 runoff election. John Young ran a strong third with 313,183 votes (28.9 percent). In the 2015 general election Nungesser prevailed, 628,864 votes (55.38 percent) to Holden's 506,578 (44.62 percent). Edwards and Nungesser, of opposite parties, assumed office on January 11, 2016.
On January 22, 2016, Guillory announced his intention to run for Louisiana's 4th congressional district in 2016. Fellow Republican and incumbent John Fleming is retiring to run for the U.S. Senate seat being vacated by Republican David Vitter.
Guillory has served on the boards of directors for the Saint Landry Parish Chamber of Commerce, the local Salvation Army, the Saint Landry Parish Indigent Defenders, and the Opelousas Daily World newspaper. He is a Rotarian and a supporter of the American Cancer Society. Guillory is Roman Catholic like his father, being an active member of Holy Ghost Catholic Church in Opelousas.
Elbert Guillory is the brother-in-law of the late Jane Nora "Genore" Guillory (1958–2000), who was brutally murdered in East Feliciana Parish. Senator Guillory and his daughter, Imani Malique Guillory, were interviewed in Investigation Discovery's 2013 Southern Fried Homicide documentary on the murder. Four of Genore's neighbors were convicted in her death.