Bobby Miller has resigned his post as president of Mount Pleasant Precinct 14 of the Charleston County Republican Party.
Miller was under fire for racially charged posts to his Facebook page.
He informed GOP Chairman Larry Kobrovsky of his decision Wednesday.
On Friday, NAACP Charleston Branch President Dot Scott condemned bigoted posts on Miller's Facebook page and called on the state and county parties to remove him from all positions of party leadership without delay.
State lawmakers Wednesday removed Miller from the Charleston County Transportation Committee, citing racially offensive posts on his Facebook account. Miller responded that someone had hacked his Facebook page and he did not post the offensive content.