brainchild
Banned
I could draft longer bills too that build on past failed bills if I had a bunch of aides and interns to do grunt work.
What can't really be easily replicated is more innate intellectual curiosity, interest in policy and details and actual governance.
What you said applies to literally every congressman/congresswoman and senator. None of them draft up these large pieces of legislation without help.
However, if your main issue is whether or not Bernie possesses the ability to meticulously articulate his policies (perhaps in a similar fashion to Hillary) then you'll need to pay more attention to his proposals in congressional hearings (they've been transcribed on the congress website), as he doesn't take that approach when speaking to the general public.