Daniel Perry was found guilty last month of shooting to death 28-year-old Garrett Foster, a U.S. Air Force veteran, at a Black Lives Matter rally in Austin, Texas.
He said the state's "stand your ground" law justified Perry's actions and could not be "nullified by a jury or progressive district attorney," Abbott said at the time.
Perry's defense lawyers said they were disappointed with the sentence, but would focus to appealing the case and cooperating with the state's pardon process.
Jose Garza, the district attorney for Travis County, where the case was tried and where Austin is located, is a Democrat.
The shooting came moments after Perry, who was driving for Uber, happened upon a group of protesters, including Foster, marching downtown.