In brief, the rude Republican has a problem with loose lips and, surprise, surprise with race.
From the NY Times
Jackie Calmes points to the biography of Mr. Wilson in CQ’s "Politics in America," which includes this line: "Wilson’s sharp and careless remarks sometimes land him in hot water." One example listed was Mr. Wilson’s constant criticisms of Senator John Kerry during the Democrat’s presidential campaign, and even includes a reference to Mr. Wilson’s characterization of the news that Strom Thurmond had fathered a daughter with a black woman. Even after the longtime Republican senator’s family acknowledged the paternity, Mr. Wilson called the notion a "smear on the image" of Mr. Thurmond.
A little on the district, also from the Times:
Mr. Wilson, 62, whose district runs from the coastal border of Georgia into central South Carolina, from Hilton Head to Columbia, was first elected to the House in 2001.
Rather than getting more popular, his races have gotten closer over time. He won with just 54% last time.