It means that the company tries to get certain people removed from the official lists (or "rolls") of persons who are registered by the government as entitled to vote in elections. If their names are removed from the lists of registered voters, then they may not then vote at the next election.
Please note that "sb" is not a standard abbreviation commonly used by native English speakers, and many will have no idea what this abbreviation means. If you want native English speakers to understand this question, you need to write out the word "somebody".
The company finds legal reasons to disqualify people, removing them from the voter registration records cum rolls cum databases; they try to get them removed because they are likely to vote for the other candidate based on demographic factors like age, income, ethnicity, etc.