I said it in another thread - there's no way insurance companies will just idly sit by and let themselves be literally outlawed out of a job. Any bill will have to either work out a way for them to continue existing, or get lobbied to death.
Not to mention the hundreds of thousands are people that are employed in the industry, as well as state run insurers.
Eradicating all of that just isn't feasible. It's going to have to be some kind of hybrid system if we want to pass it in this country.