Bernie Sanders’ proposal of ‘Medicare for All’ to replace Obamacare is being hailed as visionary by some and as politically unrealistic by others. As it is for all single-payer systems, the biggest argument against it is that it would cost too much. Sanders says it would cost more than a trillion dollars a year, but some analysts say it’s more like double that amount. As Sanders says, if Europe can do it, why can’t we?