How do we unwind today's extreme political polarisation before it tears American democracy apart? It's a challenging riddle, as many diverse factors have contributed to polarisation's rise. Inequality, demographic change, geographic sorting, the Internet and social media, the end of the Cold War - all have played a part in splitting the US electorate into two hostile and mutually uncomprehending tribes. Some of these factors are irreversible, and others look stubbornly resistant to reform.
But there is one major driver of polarisation that is directly under the control of politicians, if only they would realise it. One of the biggest fault lines in American politics, the long-running ideological dispute over the proper size of government, is based on a false dichotomy. It is time to leave that sterile debate behind.