This was due to the near-total disenfranchisement of the state's large African-American population during this time, who mostly voted Republican.
The Civil Rights era turned the state into a competitive one on the federal level, as it voted for the nationwide winner in every election between 1972 and 2004.
They were soon replaced by Democrats who established Jim Crow laws that eliminated Black political participation for nearly 100 years.
In the early 20th century, Louisiana retained a pocket of Republican strength centered around the sugar parishes west of New Orleans, where farmers favored the GOP's position on protective tariffs.
According to The Louisiana Elections of 1960, whose authors include the late sociologist Perry H. Howard, from 1920, the year of the election of Warren G. Harding as U.S. President until 1956, the reelection of Dwight D. Eisenhower, "a number of parishes, many in close proximity, have consistently supported the Republican party at close to or significantly above the presidential Republican vote average.
"[2] In the decades following the beginning of the Civil Rights Movement and a concomitant reaction against cultural liberalism, the Republicans gained strength in the conservative suburbs of New Orleans and Baton Rouge and for a time in Caddo Parish.
The political balance in Louisiana was heavily affected by the post-Hurricane Katrina departure from New Orleans.
Previously there were cultural divides between Democratic voting Roman Catholics in Cajun parts of southern Louisiana and Protestant Republican voting people in northern Louisiana, but by 2019 this gave way to a rural Republican-urban Democratic divide that characterizes other parts of the United States.
Bill Dodd, former lieutenant governor and education superintendent, in his book Peapatch Politics: The Earl Long Era in Louisiana Politics, describes corruption as "a way of life, inherited, and made quasi-respectable and legal by the French freebooters who founded, operated, and left us as the governmental blueprint that is still Louisiana's constitutional and civil law."
Dodd further notes that some attribute the corruption to "outlaws, gamblers, and fortune hunters who came off the mountains and down the Mississippi River to add their flavor to the Louisiana pot."