In his masterful new book on early America, author Myron Magnet uses concise biographies of George Washington and other Founders to illustrate why our revolution unleashed more than two centuries of freedom and prosperity. “The Founders at Home” is a work of scholarship and a labor of love, and offers vivid reminders of the courage of extraordinary individuals who birthed a new idea on Earth.

Take, for instance, the back-stabbing rivals trying to oust Washington as head of the Continental Army. Even as soldiers were leaving bloody footprints in the snow at Valley Forge, their commander had to defend himself against a vicious campaign by supposed comrades. Imagine if they had succeeded.

Or consider the unsentimental wisdom of John Jay, the diplomat who negotiated the treaty for ­independence with Great Britain and later became the first chief justice. Jay warned against the false “nostrums and prescriptions” of the ambitious and greedy, and urged his countrymen to “take men and things as they are.” Otherwise, he wrote, “the knaves and fools in this world are forever in alliance,” and self-government was doomed.

Magnet’s warts-and-all tour is so seductive in part because of our current troubles. Despite the success of the Founders’ grand experiment, events in Washington and around the world have many Americans fearing we are headed for a crack-up.

The fear provokes a wish we had a Washington or a Jefferson to guide us now. But the genius of Magnet’s book is that the “home” in the title refers not only to the actual homes the Founders built, many of which still stand, but also to the profound personal responsibility they felt to their new nation.

At enormous risk and cost, they created a model of patriotism that is not reserved for great men with lofty responsibilities. Their examples still matter because American exceptionalism ultimately is about ordinary people doing ­extraordinary things.

It is not enough to complain about our leaders and declare a pox on both their houses. We the people are sovereign and get the government we deserve. If bums are running the country, look in the mirror.

As I have said, my vote for Barack Obama in 2008 was a terrible mistake. I erred in hoping he would be what he promised to be instead of, as John Jay warned 200 years ago, what he actually was. Sadly, the rampant corruption and incompetence of his administration reveals the real Barack Obama, no matter what he says or whom he blames.

Others probably feel ashamed of their votes for Speaker John Boehner or Majority Leader Harry Reid. Their behavior also reminds us that voting carries consequences.

This does not mean that political strife is the problem. In fact, the system of checks and balances is based on the Founders’ assumption that human nature would be guided by self-interest, and that the clash of interests would produce a result that fairly represents the will of the people and the common good of the country.

But, obviously, something is broken. The balance between rights and responsibilities has been shattered and the nation’s character diminished.

The same sense of self-gratification and entitlement that infects our culture rules our politics. Elements of our government are as vulgar as the worst of our entertainment.

As Magnet shows, the Founders predicted the peril we now face. Washington saw the Constitution as but a piece of parchment that depended upon “virtue in the body of the people.”

If that virtue was eroded, he warned, by a “corruption of morals, profligacy of manners and listlessness for the preservation of the natural and unalienable rights of mankind,” America would degenerate into tyranny.

No, we are not there yet, but ask yourself this: Where on the spectrum of our history are we?

Are the founding virtues still intact, or has their spirit been eroded by the “corruption of morals”?

Are we closer today to the ideals of liberty, or to the tyranny the Founders warned would follow the death of those ideals?

Each of us should answer those questions and act accordingly. ­After all, accepting individual responsibility is the foundation of American exceptionalism.

Realty bigs in De Blas De-nial

The assumption by many New Yorkers that Bill de Blasio will be the new mayor is producing emotions that range from fear to loathing. OK, there is some euphoria, too.

But there is another reaction that amounts to delusional denial. It comes from people who should know better.

The socialist-leaning de Blasio is calling for a temporary freeze on rents in apartments that are home to more than a million people. That hasn’t happened in the 44 years that the Rent Guidelines Board has set the maximum allowable increases for rent-stabilized apartments, according to The Wall Street Journal.

Naturally, a rent freeze is unpopular to real-estate owners, yet many support de Blasio. Republican Joe Lhota opposes a freeze, but that doesn’t seem to matter to some landlords.

A spokesman for the largest owners group told the Journal: “Bill is not too smart backing this. I’m not sure if this is campaign rhetoric, but he will recognize the reality if and when he takes office.”

There you have it. The belief that de Blasio doesn’t mean what he says — he couldn’t be that dumb! — reflects more than a cynical view of politicians.

It reflects the cowardice of people who hide behind hope. They whistle past the graveyard because they find it easier to pretend the train coming their way will spare them.

Perhaps it will, but the alarm should be ringing. Rent hikes are set by nine members of the guidelines board — and all nine are appointed by the mayor.

Bet your ranch, or apartment building, that a Mayor de Blasio will get his rent freeze. Just don’t say you weren’t warned.

A righteous road rage

After Port Authority officials closed some New Jersey access lanes to the George Washington Bridge and caused massive traffic jams, Executive Director Patrick Foye demanded to know why. He called the action “abusive” and suggested the given reason — a traffic study — was a lie.

His rage is reason for hope. Every motorist encounters maddening bottlenecks caused by construction crews where the job seems to consist of standing around.

The power to make people wait is an awesome power, and it cannot have been abused only once. The career of the city’s bicycle czar is based on snarling traffic.

Pray that Foye’s demand for sanity starts a trend.

Dead letter office

“Going postal” deserves a new definition: acting suicidal.

A help-wanted ad posted openings for letter carriers in the city. The ad said, “Applicants must apply online at http://www.usps.com and have a valid email address.”

So postal officials don’t expect job applicants to buy stamps and wait for snail mail, thus conceding and adding to the very problems killing their business.