By Michael D'Antonio

(CNN) -- Though the White House had drafted a statement on the death of John McCain, it was not released. Instead, President Donald Trump tweeted "sympathies and respect" to the family, saying nothing of the contributions of the widely esteemed senator.

Nothing could tell us more about the character of the petty man in the White House than his weekend display. As tributes filled the news media -- many from McCain's political opponents -- Trump showed he lacks the common decency required of his office. After years devoted to dividing the country, he could not play the role of political healer, even to honor a man from his own party.

However, in a perverse way, Trump provided a service to the nation. He called attention to the difference between himself and McCain, giving us a chance to reflect on their disparate leadership styles.

Think of this exercise as the political equivalent of the old tale of the tape that newspapers routinely published to predict the outcome of a boxing match.

Courage: McCain demonstrated it in abundance, from his Vietnam war service in his youth to his final battle with brain cancer. Trump, who claimed bone spurs to avoid military service, once tried to show bravery by breaking with his party on gun control but retreated in less than two weeks.

Decency: The senator could scrap, but he avoided the lowest of blows. A prime example was the time he corrected a bigoted voter who attacked his then presidential opponent Barack Obama. "No ma'am," said McCain. He's a decent family man, a citizen that I just happen to have disagreements with." Trump rose to political significance via the racist "birtherism" that questioned Obama's status as American-born.

Clarity: When McCain sought the presidency the first time in 2000, his touring bus was dubbed the "Straight Talk Express." Direct and consistent, he always made his views clear to allies and opponents alike. Donald Trump's word salad speaking style suggests a man who intends to create confusion. It is the preferred approach of a con man.

Service: Coming from a family with a long record of military service, McCain devoted his entire life's work to improving the lives of Arizonans and Americans at large. Humble enough to admit that he made many mistakes, he never ceased to search for way to contribute to the greater good. Trump devoted himself to the accumulation of self-interested wealth and power. Prior to achieving the presidency, he established no record of service aside from writing checks to charity.

Honor: The true measure of a leader is how he reacts to defeat. McCain recognized there was no disgrace in losing. Though he lost the White House twice -- once to George W. Bush and once to Obama -- he reconciled with both and asked them to deliver eulogies at his funeral. Trump, who never seems to get over anything, has so dishonored the presidency that he has not been invited to partake in McCain's memorial services. He has also attacked McCain on numerous occasions, which may be part of the reason for his exclusion from the memorial.

In boxing, the tale of the tape was used to predict the outcome of an impending match. For Trump and McCain, it suggests how history will regard them in the years to come. McCain's stature seems fixed and is unlikely to change. Unfortunately, the same is true for Trump.