Democrats understand that when they are losing a political fight, their best move is to change the political lexicon. When progressivism fails, they become liberals; when liberalism fails, they become progressives. Now they’re using that rhetorical trickery to try to save the wildly unpopular centerpiece of President Obama’s first term: Obamacare. Obamacare sets up what were originally termed state health care “exchanges.” These “exchanges” were supposedly set up to pool risk between health care insurance companies. Of course, if the market saw a benefit in such pooling, it would have done so already. In fact, many insurance companies already pool...