Rock Island and Mercer counties are two of 14 Illinois counties with more registered voters than actual eligible voters, according to a study by the State Board of Elections. The report says the disparity was revealed by comparing the number of registered voters in each county to the number of people listed in the 2010 Census as being older than 18 and eligible to vote. Rock Island County lists 125,875 registered voters, although Census numbers show the county has only 114,359 residents age 18 or older. That means 11,516 people may be deceased or no longer live in the county, according to Rock Island County Clerk Karen Kinney. The report also shows Mercer County has 14,295 registered voters, while Census numbers show the county has only 12,714 residents age 18 or older. "We have to purge our records sometime this summer," Mercer County Clerk Phyllis Bewley said.... Other counties with more registered voters than actual eligible voters are Alexander, Clark, Clinton, Hardin, Ja...