I think that what Congress is now should become the house and work in the same way
The senate should come from select streams that we allow in. Really, as long as the stream is active and has more than say, 100 followers, they should be allowed to join. That stream will determine who their senator is, how long they get to be there, etc. Each stream will get 1 senator to send.
A bill will have to pass the House (Congress as is) and the Senate before the president can approve it.