A listing of active congressional candidates for the 2018 midterm elections, with some additional columns. The basis for this data is the Federal Election Commission’s candidate master file, and includes the columns described there. ProPublica has removed candidates no longer running in the general election, based on fundraising data and The Green Papers. ProPublica has added a `clean_name` column that converts the candidate name from all-capital letters and makes it more suitable for display, as well as a `url` column with the candidate's official website. In addition, we’ve added columns with the ID used by the Center for Responsive Politics and the ID used by Google’s Knowledge Graph Search, where available.