Write-ins Comprised Nearly 6% of Vote in the Pa. Democratic Presidential Primary

Although big urban counties like Philadelphia and Allegheny were among the biggest drivers of the write-in vote, some of the highest percentages were in rural counties. Write-ins made up the highest share of the vote in Elk County, with nearly 11%.

As of April 25, write-in data provided by the Associated Press appeared to be missing in Fulton, Green, Lancaster, and Monroe Counties. That affects the calculated vote shares in those counties.
Source: Inquirer analysis by Aseem Shukla of Pennsylvania Dept. of State and Associated Press data