I'm afraid that even with a soaring economy, renewed hope in the American dream, better international relations and less war, that the left won't care and still obsess over divisive social agendas. In which case this won't end well. I.e., we are heading for a civil war. The recent discussion suggesting Trump move federal agencies and assets to middle America is smart and could mitigate this coming clash.
There inlies the problem with the left. As you so rightly stated the left are obsessed with social issues. Regardless if the next few years brings us the golden era of America, the left will still not change, and work as a country together.