After some thirty-five years, the provisions of the Wright Amendment have expired, allowing expanded airline service at Dallas Love airport. Since 1979, airlines at Love have only been allowed to fly from Love to destinations in Texas and its neighboring states. Southwest was the main target of this legislation, as all the carriers at Love had been required to move to DFW when that airport opened in 1974. Southwest had not existed when the agreement to relocate all airline operations was signed, and claimed that as (at that time) it only operated within the state of Texas, the Civil Aeronautics Board had no jurisdiction. Thus Southwest's in-state operations were tolerated at Love airport, while all other air carriers flew out of DFW. Then the Airline Deregulation Act was passed in 1978, and Southwest announced plans to expand service outside of Texas beginning in 1979. The Wright Amendment (to the International Air Transportation Act of 1979) was designed to protect the huge investment of the cities of Dallas and Fort Worth, along with all the participating airlines, in DFW airport. The amendment was sponsored by Jim Wright, a congressional representative from Fort Worth. It restricted airline service from Dallas Love airport to Texas and its adjoining states (New Mexico, Oklahoma, Arkansas, and Louisiana). In 1997, the Shelby Amendment added Alabama, Mississippi, and Kansas to the list of states that could be served from Love field. Missouri was included as a result of the Bond Amendment in 2005.
Meanwhile, in 2004 Southwest announced its intention to pursue repeal of the Wright Amendment. Not surprisingly, American Airlines took the opposing side, and advocated against repealing the amendment. A compromise bill was passed in 2006 that put into place a gradual loosening of the flight restrictions at Love Field. The final date was October 13th of this year, making Love open to airline flights to any city in the nation. On that day, both Southwest and Virgin America initiated service between LAX and Dallas Love Field. Dallas is a new non-stop destination for Southwest from Los Angeles. While Virgin America had previously been offering flights into DFW, those flights are now flown into Love Field.
So LAX now has airline service to both major airports in the Dallas area: American and Spirit fly into DFW, while Southwest and Virgin America fly into Love.
For more about the Wright Amendment, I suggest this Wikipedia entry: Wright_Amendment