Views of Donald J. Trump’s presidency have become more positive since he left office‚ bolstering his case for election and posing a risk to President Biden’s strategy of casting his opponent as unfit for the presidency‚ according to a new poll by The New York Times and Siena College. While the memories of Mr. Trump’s tumultuous and chaotic administration have not significantly faded‚ many voters now have a rosier picture of his handling of the economy‚ immigration and maintaining law...