In 1916, President Woodrow Wilson won re-election on the slogan "He Kept Us Out of War," though he didn't. Four months later, he joined the Allies against Imperial Germany with another slogan: "To Make the World Safe for Democracy." That didn't work out either.
On Dec. 7, 1941, after the Japanese sneak attack on Pearl Harbor that FDR called "a day which will live in infamy," America was suddenly in the Allied fight against Japan, Nazi Germany and Fascist Italy, for the same purpose.
After the Axis was defeated, democracy was threatened almost at once by a different imperialism from Soviet Russia, which imposed communism on most of Eastern Europe and promoted it elsewhere.
In time the Cold War gave way with the collapse of the Soviet Union, only to re-emerge with the resurgence of the Russian Bear under Vladimir Putin, now our current president's best buddy. Or is he something more sinister?
In a real sense, America's fight now is one to make this country safe for democracy at home, against Donald Trump's increasing undermining of our own political process in several ways.
The most obvious is his failure to recognize or acknowledge the Russian meddling in our presidential election in 2016 and thereafter. He has repeatedly denied it despite his own intelligence community's thorough investigation.
Calling it a "witch hunt" and a "hoax" as he squirms under his Justice Department's inquiry into possible conspiracy with Russian agents by his campaign, Mr. Trump has also signaled his qualified acceptance of the intelligence community's conclusions about Russia. Yet he conspicuously failed to confront Mr. Putin directly at their summit in Helsinki, even inviting the Russian president to visit Washington, though that second summit is now delayed.
He currently is on the offensive against Special Counsel Robert Mueller in a brazen effort to discredit the man widely regarded in the law-enforcement community as its most incorruptible cop.
Meanwhile, Mr. Trump intensifies his own assault on foreign immigration that built this country and made it the symbol of opportunity across the globe. In the process, he stains our national reputation with his racist and ethnic slurs and tolerates cruel separation of immigrant mothers from their children.
Abroad, he undermines both NATO and the European Union with threats of trade wars and goes out of his way to disparage the prime ministers of Canada, Britain and Germany.
Finally, he heightens his war on American journalists, labeling them "the enemy of the people." Meanwhile, he coddles the pro-Trump Fox News and exhorts his political faithful to emulate him by watching it.
Trump's latest affront to the First Amendment's freedom of the press is to deny access to a CNN White House correspondent to open press gaggles. And he continues to attack CNN's Jim Acosta for his relentless efforts to press the president on his evasions and lies.
Other American presidents have had their difficulties and personal run-ins with the press. They have been trivial compared to the Trump assault on individual reporters and commentators, and the institution of independent print and electronic journalism.
FDR once verbally assigned a dunce cap and a stool to a reporter, and Harry Truman famously threatened violence against a Washington Post music critic who unkindly criticized the classical singing of his daughter Margaret.
Vice President Spiro Agnew asked other reporters regarding a portly and snoozing Baltimore Sun reporter of Japanese ancestry on his campaign plane, "What's the matter with the fat Jap?" These episodes were trivial compared to the serial slurs and insults marking Mr. Trump's relationship with the working stiffs of the press and television.
The general climate among journalists of various shapes and sizes over many years has been mostly cordial and professional, with many friendships struck in many hours of chatter over late-night drinks on the campaign trail.
An old hard-nosed reporter's quip holds that "the only way to look at a politician is down." But it's one that more often is honored in the breach, with Donald Trump a definite exception, as he sets out to feed the hostility he has encouraged among his faithful.
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is firstname.lastname@example.org.