Wall Street Journal data reporter Chad Day is returning to the Associated Press to be chief elections analyst.

Day is the lead data reporter on The Wall Street Journal’s national politics team where he covers presidential campaigns, elections, demographics and money in politics. He also builds newsroom tools that help reporters explore data to better understand the changing American electorate.

He joined the Journal from the investigative team at the Associated Press, where he covered special counsel Robert Mueller’s investigation and the 2016 presidential campaign.

He has also previously worked at the Arkansas Democrat-Gazette and the Kansas City Star.