Historically, this primary election has been much more important in the Republican Party's nomination process, considered a "firewall" that could permanently eliminate any/all serious rivals to the winner.
[3] It is meant to force the various factions of the party to decide quickly on and unite behind a single candidate and avoid wasting precious time and resources on a drawn-out battle between their own candidates, that would divert the party's focus from working to defeat the Democrats' likely nominee.
Since its 1980 inception, the winner of the Republican South Carolina primary has always become the eventual Republican National Convention nominee for that fall's general election,[4] with one exception, the 2012 primary, in which eventual Republican nominee Mitt Romney finished second, behind winner Newt Gingrich (who would go on to suspend his campaign before that summer's convention began).
In 2008, the Democratic South Carolina primary took on added significance because it was the first nominating contest in that cycle in which a large percentage (55 percent, according to an exit poll[5]) of primary voters were African Americans.
[6] In 2020, it was also described as a "firewall" for Joe Biden, where he had considerable leverage over his opponents, particularity with African American voters.