Few elections can be cast as resting on a single issue. But no matter whether voters support the president or the former vice president, one issue stands above the others. It is decency. Whatever one thinks about Joe Biden, he is a thoroughly decent man. Even former Defense Secretary Robert Gates who savaged Biden in his memoir writing that every foreign policy decision Biden made was wrong, then went on to praise the former vice president’s character. Of all the words applicable to the president, decency is not on the list. In his presidential campaign, Trump mocked Gold Star parents who lost sons in battle; people with handicaps; immigrants; and women. Caught on an Access Hollywood tape, Trump bragged to reporter Billy Bush how his celebrity status allowed him to grab a woman’s private parts. Inexplicably, Trump survived that extraordinary display of indecency.Trump has used racial slurs in the past. He has been coarse in conduct willing to concoct false stories such as claiming President Barack Obama was born in Kenya. The Washington Post catalogued nearly 25,000 instances where the president made false, wrong and other misstatements since taking officeEarlier this month, Jeffery Goldberg’s Atlantic explosive story accused the president of calling U.S. war dead “losers and suckers.” Four separate anonymous individuals claimed to have been present when the president allegedly made those and other disparaging statements about war dead. Reporters including from Trump friendly Fox confirmed the basis of the story from other sources. Many of the president’s supporters have ignored or dismissed the president’s latest transgression as fake news or a hoax because he delivers on his promises. But, as in baseball, in politics three strikes should be enough to declare a batter out. Strike one was Trump’s comments on the late Senator John McCain snorting that he did not like people who were captured in war.McCain was self-effacing about what he called his own meager skills as a pilot recalling how he was able to knock down a North Vietnamese surface to air missile with his Skyhawk jet. Where McCain displayed uncommon valor as a POW went beyond verbal abuse of his guards. McCain, whose father was the senior military commander in the Pacific during his captivity, refused to accept early release from the Hanoi Hilton. That courage was worthy of a Congressional Medal of Honor. Strike Two was Trump’s repeated refusal to press Russian President Vladimir Putin on intelligence reports that Moscow was paying bounties to Afghan Taliban for killing Americans. That report still has not been confirmed or denied by senior officials. Given the president’s antipathy to receiving negative reports on Russia, this behavior comes as no surprise.Strike three was the latest charge that Trump slandered Americans killed in action as “losers and suckers.” The allegations, that have been strongly denied by the president and White House, referred to a 2018 visit to France when Trump declined to pay his respects to a cemetery honoring Marines killed in the famous World War I Battle of Belleau Wood, attended by other world leaders. Unfortunately, none of these anonymous sources have revealed their identities to give the story the complete credibility it needs. Fearing reprisals that led to LtCol Alexander Vindman’s forced retirement after he testified to the House impeachment proceedings over the president’s threat to withhold funds from Ukraine, do not expect that silence to be broken.The evidence to support the Atlantic story remained circumstantial. Trump has used racial slurs in the past. He has been coarse in conduct willing to concoct false stories such as claiming President Barack Obama was born in Kenya. The Washington Post catalogued nearly 25,000 instances where the president made false, wrong and other misstatements since taking office.Politics are not meant to be fair. Had President Obama been accused of calling Americans killed in action “losers and suckers,” Republicans would have gone to the barricades as they did over the Benghazi Hearings wrongly blaming Hillary Clinton for the death of the American Ambassador to Libya, Chris Stevens, murdered by terrorists. And Trump has weathered this storm.No matter the polls, this election almost certainly will be razor thin. The battle royale over replacing Associate Justice Ruth Bader Ginsburg this Congressional session will only harden both sides against the other. Not even that smoking gun is likely to cause a change in many voters’ minds. Although, if either candidate developed a life threatening condition or was incapacitated by a stroke or heart attack, that might make a difference.During the Senator Joe McCarthy-Army Hearings, Roy Cohn was McCarthy’s counsel and went on to be a mentor to young Trump. Joseph Welch, representing the Army, destroyed McCarthy and Cohn by asking the senator “have you no sense of decency sir?”That question applies today: “Mr. President, have you no sense of decency?”Dr Harlan Ullman, a veteran of the Vietnam War in command of Swift Boats in over 150 missions and operations, is UPI’s Arnaud deBorchgrave Distinguished Columnist. He is Senior Advisor at the Atlantic Council and his next book is The Fifth Horseman: To Be Feared, Friended or Fought in a MAD-Driven Age.