I return to Europe from the US with a clear conclusion: American democrats (lowercase d) have 400 days to start saving US democracy. US democracy needs Congress, the principal check on presidential power envisaged in the US constitution, to start doing its job again. To name just four: excessive executive power; chronic gerrymandering; endemic violence; and the way a would-be authoritarian can exploit the intense capitalist competition that permeates every area of US life. Throughout the 20th century, presidents of both parties extended the “executive power” that is so ill-defined in article two of that constitution. The single most important thing for the Democrats in the next 400 days is therefore to bring those economic costs irresistibly home to voters.