Americans have seen the last four presidents as illegitimate. Here’s why.

It's tempting to see the entirety of Donald Trump's story as unprecedented, but is the fourth consecutive president to assume the office with a segment of the electorate questioning his legitimacy. On that score, Trump doesn't represent a new crisis for American democracy but rather an escalation of one that's been building - one that we've all played a role in creating and that he has deftly exploited to his advantage.

We used to argue over whether new presidents had a “mandate,” which was a more polite way of raising the legitimacy question. After the 1992 election, Senate Minority Leader Bob Dole said President-elect Bill Clinton didn't have a mandate to press ahead with any sweeping changes because he'd obtained only 43 percent of the popular vote in a three-way race. Republicans convinced themselves that third-party candidate Ross Perot had cost them the election, taking more votes away from George H.W. Bush than from Clinton. They were quick to accuse Clinton in his first year of liberal overreach for pressing to allow gays in the military, raise energy taxes and take on an ambitious overhaul of the health care system. Anger among conservatives that Clinton would illegitimately (in their view) push such an agenda led to the so-called Gingrich Revolution in 1994 and fed any number of conspiracy theories and led Republicans to gleefully pursue Clinton's impeachment during his second term.

Then in 2000 came one of the more contentious presidential elections in U.S. history - not because of the substance of the campaign between Al Gore and George W. Bush, two amiable and seemingly moderate candidates, but because the result was too close to call for weeks. It took a U.S. Supreme Court intervention to put an end to the indecision. Compounding the muddled nature of the outcome, Bush obtained half a million fewer votes in the popular count nationwide. Some members of the Congressional Black Caucus (including Rep. John Lewis, D-Ga., who forcefully questioned Trump's legitimacy this past week) refused to attend the inauguration. I can remember all the debates then among fellow journalists and friends about either the necessity, or the peril, of “normalizing” such an abnormal, unsatisfying result with a “normal” inauguration and all the other trappings afforded an incoming president.

We tend to forget the extent to which #notmypresident could have been a trending hashtag in those early Bush days - if hashtags had been around - because everything would soon change, on Sept. 11, 2001. After the terrorist attacks, Americans rallied around their president, as we always tend to do in wartime, and the grousing about his legitimacy or mandate stopped. But a few years later, with mounting disillusionment over open-ended military campaigns abroad and a sense that the administration had launched the Iraq invasion on false pretenses, millions of Americans once again began to question not only Bush's judgment but also his legitimacy. None other than New York real estate tycoon Donald Trump called for Bush's impeachment.

The impulse to disqualify, rather than merely debate, leaders we don't agree with intensified in the late 2000s. There was no disputing the mandate conferred upon Barack Obama by his resounding 2008 win, so the questioning of our first African American president's legitimacy swirled around the underhanded, racially motivated and absurd allegations - peddled by our new president, among others - that Obama wasn't a natural-born citizen. Newt Gingrich spoke for many in 2010 when he accused the president of being beyond the American mainstream, pursuing instead a “Kenyan, anti-colonial” worldview.

Given our propensity to question the legitimacy of leaders we don't agree with, it's hardly surprising Lewis and others began questioning Trump's legitimacy before he took the oath. The tenor of his public rhetoric and behavior; his considerable 3 million-vote deficit in the popular vote; the FBI director's erratic intervention, now under investigation, in the final days of the campaign; and the Russian government's attempts to influence the outcome in Trump's favor provide fodder for those inclined to dismiss a president they oppose. Trump has taken to calling “fake news” any news he doesn't like, but for millions of Americans he is about to become their “fake president.”

What is it about the past three presidencies that helped bring us to this moment? That question will no doubt inspire many dissertations in the coming decades, but one obvious similarity is that the Clinton, Bush and Obama administrations, unlike those that came before them, had to navigate in a political environment shaped by the close of the Cold War, the rise of instantaneous, doomsday-style political fundraising, the emergence of a highly balkanized and ubiquitous 24/7 media and the disruption of traditional politics by the Internet and social media.

These are somewhat familiar, overlapping themes, though we often make a glaring omission in how we talk about them. With the end of the Cold War and its threat of nuclear annihilation, the stakes seemed lower, as did our need to defer to presidents on foreign policy or anything else (the two years after 9/11 were a reversion to Cold War days in terms of how opponents dealt with Bush). The flood of money into politics - money that could be raised easily by groups other than the traditional political parties, at the click of a button - encouraged a rhetorical arms race of dystopian depictions of what had become of Washington. It is much easier to get people to send you $20 if you accuse the president of being a threat to the American way of life instead of an honorable man with whom you happen to disagree on a certain topic. And we're all familiar with how changes in media in this age of 24/7 cable news (Fox News launched in 1996 to challenge the cautious objectivity of CNN) and of infinite online opinions have helped poison, and add a frenzied quality to, political coverage and discourse.

The omission in how we talk about the hyperbole in our politics and civic life is that we conveniently take ourselves out of the picture. We talk about all this with detached regret, as victims of distant politicians' antics, when we are in fact protagonists in this tale, helping to determine the tenor of our politics. The internet and social media have engaged millions of Americans in politics more directly than ever before, and the results haven't been pretty.

If you're passionate about politics and follow it closely, think about how people in your circles have talked about the past few presidents, at the dinner table or online. I can recall conservative friends back in the 1990s calling Clinton (the free-trading, bank-deregulating, Serbia-bombing Democrat) a socialist and then being surrounded by friends calling Bush (the pro-immigration, Medicare-expanding, Muslim-embracing Republican) a fascist. And the zealous, irrational epithets only ratcheted up from there. Obama was often called a socialist or a Bolshevik even as he disappointed his most ardent supporters by coming to Wall Street's rescue during the financial crisis. By the time the 2016 presidential campaign was underway, neither Democrats nor Republicans retained enough credibility in sounding the alarm about Trump being outside the mainstream; they had cried wolf too many times.

This has left us with President Donald Trump: a leader befitting our own hyperbole. It's convenient to talk about the Trump phenomenon as if it were an errant asteroid hitting Washington, destroying our harmonious politics out of the blue, but it's also dishonest.

It's desirable, and quintessentially American, to strenuously oppose policies and ideas we disagree with. But the haste of recent years to delegitimize opponents, and to call them un-American, is itself un-American. It leaves us with a bankrupt, even illegitimate, politics, devoid of shared narratives, aspirations, values and, increasingly, facts.

Adrés Martinez is editorial director of Zocalo Public Square, for which he writes the Trade Winds column. He teaches journalism at Arizona State University. From the Washington Post.