What's the source of the data once an address is submitted? I tried to do a similar project during a hackathon and all of the APIs I found were either dead or insufficient.
https://developers.google.com/civic-information/
The API has a representativeInfoQuery to list your elected representatives, and a voterInfoQuery for current election information.
Details and examples are here:
https://developers.google.com/civic-information/docs/using_a...
And this page discusses the quality and limitations of the data:
https://developers.google.com/civic-information/docs/data_gu...