Bernie isn't stupid. He knows this won't pass.
He's only introducing it as a strategic move since the GOP blundered on the health bill.
He's playing chess not checkers.
The ACA has gaps and this will help get it back in the public consciousness.
Unfortunately there's no party looking to support this tactic. If this were the Democrats' platform, this would give people something to vote for in 2018. Back in 2008/9 Obama was against the insurance mandate and for the public option, but when it came time to pass healthcare reform there were a handful of Democrats who made the public option an impossibility
The ACA passed instead without a single vote from the Republicans. There are countries that have universal coverage through the mandate plan, but in every other country that uses this method, the mandated plans are nonprofit. The fact of the matter is that our political system is more concerned with company profits than the well being of the public at large.
Republicans makes this a reality, but so do some Democrats.. and the thing is, whenever someone on the liberal side tries to call out the corporatist Democrats, that person is shamed into a corner. Democrats are better at shaming progressives than they are at shaming the corporatism in their own party.
We are unfortunately a political system that is driven by special interest.. it's a reality in both parties, but it is especially a reality in the Republican party