Whether he is dealing with the loss of a family member, the deaths of nearly 150,000 Americans in a surging pandemic, more than 30 million people out of work or the racial unrest brought on by the killings of African-Americans by white police officers, President Trump almost never shows empathy in public. A book published this summer by his niece, Mary L. Trump, has focused renewed attention on this trait.

Mr. Trump has held no national day of mourning for victims of the virus. He has surrounded himself at Rose Garden events with business executives pushing to reopen the economy rather than families who have lost jobs or loved ones. In grim speeches over the Fourth of July weekend, he angrily denounced what he branded as the “new far-left fascism” and never once mentioned George Floyd, the Black man whose death in police custody has set off worldwide protests over racial injustice.

There are many reasons — denial and disorganization among them — that Mr. Trump’s handling of the virus has led to catastrophic and overlapping crises in the United States. But even Republicans say one primary cause is the president’s failure to put himself in the shoes of others and harness their pain. His unwillingness, or inability, to comfort an anxious nation has appalled critics, stunned allies and aggravated White House staff members, who remain perplexed why this most basic part of presidential leadership eludes him.