On my office wall hangs a brilliant drawing. It is the now-famous Obama-Washington hybrid that graced the cover of the New Yorker on January 26, 2009. Obama's (then-unwrinkled) face peers sternly from beneath a powdery white George Washington–style wig. Published well before Hamilton made multiracial Founding Fathers seem ordinary, the cover depicts his torso wrapped in an 18th-century neck scarf and jacket.

My students — some of whom were 10 when Obama was elected — are intrigued, even confused. How is Obama like Washington? they query.

It's a very good question. But I think the answer is, really, not at all.

Oh, sure, I could come up with reasonable responses. Perhaps the messiah complex that was bestowed on Obama in the months leading up to his jubilant election, much like the near deity status Washington received after the Revolutionary War.

Or the hope for a new beginning by the general electorate, like the start of a new nation. Or the parallel "firsts" — first black US president, first US president.

Perhaps — most provocatively — the irony of a black president in the slave-owning Washington's garb.

But mostly: not at all.

Recently, writers and pundits have been on a quest to find historical analogs for people, parties, and movements in our own times. Trump is like Hitler, Mussolini, and Napoleon; the imploding GOP getting rid of one ill-suited candidate after another is like Robespierre in the French Revolution, who stuck the executioner in the guillotine because there was no one left to behead. The late Supreme Court Justice Antonin Scalia was like Robert E. Lee.

Politically motivated comparisons go both ways, of course. Remember Obama as Machiavelli's prince? Oh, and how Obama was like Hitler? But that's so 2015.

Such comparisons are tempting. I should know —history is my craft. I teach early American history at Brown University and received my doctorate in American religious history from Harvard.

In the rush to make history more "relevant" or "engaged," I join my fellow history professors and teachers across the country in trying to connect the past to the present. History is alive, and she has a lot to teach us. I quote William Faulkner (what history professor hasn't?) who famously declared: "The past is never dead. It is not even past." I start each and every class with a few minutes to consider items in the news that relate to my Colonial-era topics.

But not all uses of the past are created equal.

Really? Trump is like Hitler? The egotistical buffoon who sees himself as his own primary foreign adviser and changes his views on abortion three times in one day is like the despicable human being who oversaw the death of 6 million Jews? Hitler comparison has become so common over the years that it has its own probability factor known as Godwin's Law.

The GOP's current crisis mirrors the French Revolution? Ted Cruz is like Robespierre? Please. You are granting way too much historical importance to the self-implosion of a political movement that rose to power over the past 30 years on a platform of moralistic piety, militarism, anti-abortion, and xenophobia.

I get it — history can be boring. Goethe once said, "I hate everything that merely instructs me without augmenting or directly invigorating my activity." People aren't always sure what to do with history. But the laziest use is to make facile comparisons between then and now, this person and that.

Mostly these comparisons are shallow and not rooted in any depth of meaningful knowledge of the past. They rely on caricatures and selective historical tidbits in a way that, indeed, just about anyone can be compared to anyone else.

Even worse, they dumb down our political discourse, cheapen the actual realities of the past, and rob us of the opportunity to genuinely understand and learn from the past.

These comparisons tend to come in two forms: those meant to elevate, and those meant to denigrate. Both use historical comparisons to accomplish their goals. The former seeks to gain credibility by tying present people and movements to past heroes; the latter seeks to discredit by comparing the present person or movement to the most egregious examples of historical evil.

If comparisons are meant to elevate, we find people and movements in the past to which we can hitch our own cause. The Tea Party comes to mind. They resent what they see as an intrusive, bloated, centralized government and burdensome taxes, just like the Boston Patriots of the 1770s despised the oligarchic excesses and taxation of King George III and Parliament.

Same, right? Actually, no. The Tea Party's 15 nonnegotiables fascinatingly intermingle the present with the past. Complaints about taxes are right next to concerns regarding unauthorized immigrants, stimulus packages and bailouts, and "traditional family values" (by which they surely don't mean to idolize the 30 percent out-of-wedlock pregnancy rate found in the Revolutionary era, do they?).

By associating their 21st-century political agendas with the 18th-century American rebels, modern Tea Partiers collapse the distance between then and now in order to legitimize their cause.

The denigrating kind is more familiar. It goes like this: We find the worst villains or institutions in the past and make comparisons at will. Hitler. Mussolini. Andrew Jackson. Machiavelli's prince.

Slavery is another popular go-to comparison. But ... sorry, Kesha: Recording contracts are not like slavery. And Republicans: Neither is the national debt, Obamacare, income tax, or gun control. Or the TSA, global warming, or Affirmative Action.

The list is never-ending, it seems. Former NBA commissioner David Stern is like a plantation overseer. College sports, abortion, the treatment of animals — all like slavery. Except they aren't (although college sports are clearly in the realm of sketchily inequitable, as South Park's trenchant 2011 episode suggested).

In fact, presidential hopeful Ben Carson's comparisons to slavery were so common that he was parodied as suggesting that even buying a Megabus ticket is like slavery (which, sadly, is almost believable).

Too often, people grab a quick, sexy, polemical, historical analogy to make a point or further their cause. The problem is these easy analogies are extremely shallow and based on a superficial knowledge of the past.

History is not a deck of cards from which to randomly draw for comparative purposes. It is an immense repository of human thinking, doing, and being that can and should help us be slightly less narrow-minded and shortsighted than our forefathers and foremothers sometimes were. Good uses of history require more substance, unpacking, and analysis than a few quick sound bites can provide.

Sure, I know. People who make historical comparisons don't actually believe that Ted Cruz is like Robespierre. But then why bother? The reason there aren't longer expositions of how exactly Trump is like Hitler is because, well, very quickly the analogy would break down. Male ... popular ... racist ... oh, never mind. These analogies are usually politically motivated, shallow, and intended to shock or damn. It's just lazy, and more politics as usual.

Politics as usual, perhaps, but with a cost. There are negative public and intellectual consequences of such comparisons.

Simplistic historical analogies do a sort of epistemic violence to the past and to ourselves. When we say that Trump or Obama is like Hitler, we slowly water down our actual knowledge of the very historical things we are using for comparison. When people link their frustration with the Affordable Care Act or gun control to slavery, they greatly diminish the historical magnitude and importance of a horrific historical reality that irreversibly altered the lives of 10 to 12 million enslaved Africans who were forced across the Atlantic to the Americas between the 15th and 19th centuries. Scholars speak of a "social death" that came from the incredible violence, emotional damage, and physical dislocation that took place during the Middle Passage and beyond.

Such comparisons also insult the millions of descendants of these enslaved Africans, many of whom were either born into slavery in the Americas or else born in oppressive times that continued the legacies of slavery and racism, such as Jim Crow laws, segregation, lynchings, and a vast curtailing of black people's civil rights.

It papers over the clear historical links between black slavery and the rise of the prison-industrial complex, due in part to the provisions of the 13th Amendment, which prohibited slavery and involuntary servitude in the US "except as a punishment for crime whereof the party shall have been duly convicted."

History is more like electricity shooting down the string of Franklin's fabled kite: wild, with alternating currents and unexpected twists, offshoots, and end results

Essentially, by falsely comparing things in the present to slavery we rob ourselves of the opportunity to learn more about actual historical slavery. Or, as we are realizing, slaveries. Recently the field of early American history has been all abuzz with our growing understanding of the depth and magnitude of the enslavement of Native Americans over time. Scholars now estimate between 2 and 4 million American Indians were forced into slavery between 1492 and 1850.

Hardly anyone was untainted, including our cherished Puritan forebears, who not only held African slaves but also waged wars against New England Natives, kept some as slaves for themselves, and sent others to work on plantations in Barbados and Jamaica. Some enslaved Natives even ended up in Spain, Morocco, and the Azores.

And this is to say nothing of ongoing modern slavery, which afflicts roughly 35.8 million people globally each year.

Flippant comparisons also belittle and ignore the way that historical trauma creates immense ongoing psychological pain and tangible collective struggle that continues through generations, even up through the present.

Perhaps this is the deepest meaning of the idea that the past is never dead. "Shall we never, never get rid of this Past?" Holgrave anguishes in The House of the Seven Gables. "It lies upon the Present like a giant's dead body!" Indeed, the past imposes itself upon us, but especially heavily upon those whose ancestors experienced collective and sustained abuse, mistreatment, and genocide.

Part of me understands the impulse behind these comparisons. After all, isn't this basically an outgrowth of the ultimate historical truism? "Those who don't know their history are doomed to repeat it." If you listen closely, there is fear intermingled with the politicking. One charitable reading of why people make these comparisons is that they fear we will end up in unpleasant and unfortunate situations that are like past circumstances. Behind the charge of Trump being a fascist is the fear that Trump, if elected president, will rule unilaterally in a way that oppresses certain segments of the population.

The only problem is that history really doesn't repeat itself. If anything, it remixes themes, reprises melodies, and borrows nasty racist ideologies. There are no exact historical analogs to today's politicians — jackasses or saviors. To be sure, American history is full of jackassery, particularly where politicians are concerned. A hundred scenes come to mind.

As Mark Twain supposedly said: "History doesn't repeat itself. But it rhymes." And it is in the rhyming that history still plays an important role.

Historian William Bouwsma once noted that the past is not the "private preserve of professional historians." Rather, he argued that history is a public utility, like water and electricity. If Bouwsma is right, the kind of history most people want is like water: clear, available at the turn of a knob, and easily controllable. But really, history is more like electricity shooting down the string of Franklin's fabled kite: wild, with alternating currents and unexpected twists, offshoots, and end results.

The true lessons of the past are about paths already taken, and to our shame. Anti-immigration? Yeah, we've been there. Alien and Sedition Act. No-Nothing Party. Anti-Catholicism. Chinese Exclusion Act. Indian removal. Japanese internment camps. Tried that — and later regretted it.

Voting for Trump won't bring about an American Holocaust, but it could usher in a new yet rhyming phase of history in which US citizens and immigrants from certain backgrounds are targeted and legally discriminated against, have their civil liberties curtailed, and even get forcibly relocated into "safe" areas. Hard to imagine? Not for the Boston Globe, with its recent Trump-inspired future front page.

American history, as Jon Stewart brilliantly reminded us, is at its core a series of events in which the current dominant group (no matter how recently established) dumps on the newest immigrant group. Catholics. Jews. Irish. Asians. They've all been in the crosshairs. All of them have been viewed as just as dangerous as the current out-group: Muslims.

Radical Catholics might not have been strapping bombs to their chests in a misguided politicization of their religion, but Catholicism was viewed as far more sinister in the 19th century: Catholics could be taking orders from the pope himself, who was clearly trying to undermine the very democracy and Protestant individualism that the newly united country stood for.

Of course, all of this was nonsense, but it didn't stop the general American public from holding on to such notions for more than a century. Suspicions of John F. Kennedy ran so high that he had to give a sermon in 1960 specifically to allay fears of a Catholic conspiracy.

Mitt Romney stole this sensible move from JFK's play book when he delivered a similarly fear-allaying speech in 2007, promising his Mormonism would not dictate his decisions as commander in chief. Just as Utah Sen. Reed Smoot had to prove when he was elected to Congress in 1904.

Ironically, despite being a nation that is largely a motley collection of immigrants, we have a long and sad history of pretending that immigrants are the problem, instead of the core of what makes America great. Even someone as racist and xenophobic as Trump has employed thousands of immigrant workers all over the continent in building and running his real estate empire (including the worker who hung a Mexican flag at the top of one of his towers in Vancouver).

Is there a proper use of the past? Not all historians agree. In some ways, the past does not need to be usable in order to be useful. The past matters in its own right, not just for what it can tell us in the present. The historical enterprise is about learning, finding, understanding, and interpreting; application comes later (if ever, some would say).

Sometimes the lessons learned are so nuanced they will never make the headlines or sway elections. The tenderness of letters between John and Abigail Adams. The courage of Civil War soldiers marching to an almost certain death. The beauty of poems by Phillis Wheatley, the first published African-American poet. Heart-wrenching pleas for justice by Native Americans in land cases. The incredible inhumanity of slave masters who flogged and branded their slaves to death.

What we want to remember and what we ought to remember are not always one and the same

And yet, the impulse to turn to the past remains strong — specifically, to connect it to the present. In 1918, just after the international horrors of World War I, writer Van Wyck Brooks argued for creating a usable past. "What is important for us?" Brooks pondered. "What, out of all the multifarious achievements and impulses and desires of the American literary mind, ought we to elect to remember?"

Brooks's impulse to create a usable past resonates with a vein of popular scholarship that seeks to create a "national heritage" by telling comforting stories about past American heroes. The wider American public yearns for such storytelling, which is why the road to the Pulitzer Prize is littered with books about great white Founding Fathers.

But what we want to remember and what we ought to remember are not always one and the same. It is in the nefarious alchemy of heritage history that enslaved Africans become "workers," and Native Americans and colonists are pals. Thanksgiving, right? Hardly. There's a reason why since the 1970s Native nations have called it a national day of mourning.

Which is why there are other, more productive uses of the past. History as critique, honest assessment, and self-examination. Thinking long and hard about the treatment of Native Americans, past and present. American imperialism. Slavery, and its intertwining with the rise of modern capitalism. Xenophobia. Suppression of women's rights. These stories need to be told and retold, painful as they may be.

But perhaps the most powerful use of the past is history as explanation. If simplistic comparisons cheapen the past and dumb down our public discourse, using the past to understand how we got to where we are today is actually productive. It increases knowledge, broadens our perspective, and helps connect dots over time.

For example: If Americans truly want to understand this GOP moment, we need not look to revolutionary France, but to the circa-1970s US, when the modern Republican Party was born. I know, Republican pundits like to call themselves the "party of Lincoln," but that is mostly nonsense. For almost a century after 1865, most Southern conservatives were Democratic, precisely because Lincoln — of the newly minted anti-slavery Republican Party — forced the South to abandon slavery as a result of the Civil War. Southern Democrats were forged into Republicans in the civil rights movement as racial concerns joined — in the 1970s — with powerful cultural and religious ideas such as anti-abortion.

To compare Trump to Napoleon or Hitler is to make a vacuous historical comparison that obscures more than it reveals. But it is actually constructive to try to understand Trump as a fairly logical outcome of some of the cultural impulses that drove the moral majority and the religious right in the late 1970s and early 1980s. It tells us how we got here and, potentially, how to move forward.

Done well, history gives us perspective; it helps us gain a longer view of things. Through an understanding of the past we come to see trends over time, outcomes, causes, effects. We understand that stories and individual lives are embedded in larger processes. We learn of the boundless resilience of the human spirit, along with the depressing capacity for evil — even the banal variety — of humankind.

The past warns us against cruelty, begs us to be compassionate, asks that we simply stop and look our fellow human beings in the eyes. All of us — grandstanding presidential candidates and partisan tweeting voters — could use a little more of this kind of history, not less.

Why, then, is Obama-Washington still on my office wall? Mostly to remind me of the irony of history. Of its complexity. That the past might not be past but is also not the present. It is a warning against mistaking progression in years with progress on issues. It is a reminder that each one of us plays an important part in the unfolding of history.

Linford D. Fisher is an associate professor of history at Brown University.

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