This year, for the first time in our history, there are three American presidents who were born in the same year. We have had three pairs of presidents born in the same year — the very unlike John Quincy Adams and Andrew Jackson, in 1767; Richard Nixon and his surprise successor, Gerald Ford, in 1913; Jimmy Carter and George H. W. Bush, 1924.

Now we have three presidents who were born in the calendar year 1946: Bill Clinton in August, George W. Bush in July and Donald Trump in June. Note that all three were born just a little more than nine months after V-J Day. (For younger readers, that's the end of World War II.)

1946 is generally taken as the first year of the Baby Boom, the remarkable and unpredicted sudden surge of births in the United States and numerous other countries. It continued, by the usual reckoning, until 1962, when births sharply plummeted — which means it includes at the tail end 1961, the year Barack Obama was born.

The leading edge of the Baby Boom, the oldest members of an enormous age cohort, has made its mark on American life. Growing up in an era of postwar conformity, they insisted on doing their own thing. They listened to and played rock and roll, the first adolescent music genre. They participated in student riots. Their high school class of 1964 had the highest test scores in history.

Compared to their parents, they attended college more and served in the military less. All seven presidents born between 1908 and 1924 were in some form in the World War II military. Two of the 1946 presidents never were in the military at all, and one served in the Texas Air National Guard.

Two were the sons of men highly successful in quite different fields, one of a mysterious figure who died before he was born. But all three graduated from prestigious universities — Georgetown and Yale Law, Yale and Harvard Business, the Wharton School at Penn.

Of course, each was different. Bill Clinton was a political prodigy, with the capacity to understand public policy and its political implications seemingly off the top of his head. He started his political career early, running the 1972 McGovern campaign in Texas and almost upsetting a Republican congressman in 1974. In 1976 he was elected attorney general and in 1978, at 32, governor.

He had luck, and dazzling political skills to take advantage of it. When his career seemed to be winding down — he was re-nominated and re-elected by lackluster margins in 1990 — he took a chance on running for president against an incumbent who started the year with 91 percent approval. That guaranteed weak Democratic competition, and Ross Perot's surprise candidacy, which dislodged Bush, and surprise (and temporary) withdrawal boosted Clinton.

As president Clinton had his stumbles and unique disgrace. He was disorganized and undisciplined, but also constantly adapting and revising, re-writing State of the Unions on his ride to the Capitol. The public mostly approved.

George W. Bush was in some ways the opposite. After an unsuccessful House race in 1978, he mostly laid aside politics. After his father lost to Clinton, he seems to have believed that God put it in his way to run for president, and strove to tutor himself to do the best job possible.

His strength was steadfastness, his weakness (as always, the same quality) stubbornness. He was agonizingly slow on mid-course correction, notably on Iraq but also on Social Security reform.

Bush's political strategy, designed to keep Texas from being the next California, worked, but gave him only small electoral vote majorities. When his job approval dropped, in 2006-08, his party took its worst thumpings in the last 25 years.

Donald Trump's strategy followed not Bush but Ross Perot. He bet that his trademark stands on trade and immigration—different from every president's since Eisenhower—though costing him votes of college graduates in California, Arizona, Texas and Georgia, would gain him enough non-college votes to win.

The bet paid off. Trump ran behind Bush in those states but it cost him zero electoral votes. But swings by non-college whites in Florida, Pennsylvania, Ohio, Michigan, Wisconsin, Iowa and Maine 2 gave him 100 electoral votes twice won by Barack Obama.

Was that shrewd insight or blind luck? Either way, it perhaps owed something to Ross Perot (born 1930), who helped make each of these boomers president.