Define a "shared" congressional district system to be one where in any district the top two candidates are elected and each get a fractional vote in Congress according to their share of the vote. E.g., three candidates A, B, and C receive 42%, 38%, and 20% respectively. Then A gets 0.525 and B gets 0.475 of a vote in Congress, while C remains unelected.

To extend this to the entire country, current districts are made twice as large, so the total number of representatives does not change. And vote tallying in Congress would require counting fractional votes.

Some possible advantages are:

* Gerrymandering becomes much less worthwhile, less need to redistrict
* Fewer people with no local representation, e.g., more Republicans in CA and more Democrats in TX get a voice.
* Less geographical divide between the parties

**Would it take a Constitutional amendment to make it happen?  

Could it be done by an act of Congress?**