I think the interesting lesson here is that even marketplaces should be competitively constructed - i.e., there should be significant price-competitive pressure

I think the interesting lesson here is that even marketplaces should be competitively constructed - i.e., there should be significant price-competitive pressure to deliver goods and services; just letting the government to facilitate marketplaces removes price competition from the marketplace itself. I'm not suggesting that the government create a meta-marketplace for health insurance marketplaces. Just that it isn't as efficient as some people think to introduce a powerful federal competitor with 'unfair advantages' like public funding into the health insurance selection market.