On Saturday, January 21, the Women’s March on Washington D.C. inspired millions of men and women around the globe to march in solidarity. As demonstrated by numerous colorful and clever signs, the protests showcased a wide range of issues, including Black Lives Matter, reproductive rights, and the environment.

Though the causes and protesters represented were diverse, one issue – one man in particular – was present at every single march: Donald Trump.

From apparel referencing Mr. Trump’s comment that Hillary Clinton is a “nasty woman,” to creative signs with phrases like “We shall overcomb” and “Super, callous, fascist, racist, extra braggadocious,” much of the marchers’ energy was focused directly on the freshly inaugurated American president. One sign called him “Twitler.”

Marches on Washington D.C. are neither a new nor an uncommon occurrence in American history. Such large, organized efforts, however, to protest not just the president’s administration or Congress, but the president himself, are a later development.

Much of the credit for such a march goes, in a way, to President Richard Nixon.

When the Watergate scandal broke in 1973 – and it was later revealed that Nixon used his executive powers to cover up efforts to wiretap the Democratic Party’s headquarters – it greatly increased the already substantial doubt and distrust among the American people toward their elected officials. Some began to suspect that all politicians might participate in crimes like Watergate.

Watergate shook the American political system to its core. On August 26, 1974, for example, U.S. News & World Report reported that the presidential relationship with not only Congress, but also the people, was damaged forever. Politicians now had an even stronger reputation for being seedy and corrupt and, as Harvard political scientist Richard Neustadt said at the time, those who sought a better image would need to bend over backwards to prove to the American public that they were different from other politicians.

The lasting effects of Nixon’s disgrace and resignation were obvious not only in the 1970s, but continue to reverberate in today’s American political culture. In the 2016 election, candidates like Trump and Bernie Sanders found popularity with their “outsider” status. Ted Cruz bragged about the fact that his fellow senators disliked him. Trump, in his inaugural address, promised to take away power from Washington politicians he said were reaping rewards to the detriment of the American public. Since 1974, the American electorate has searched for a politician who does not seem like a politician – someone trustworthy and relatable, somebody one could have a beer with.

Richard Nixon, more than any other political figure, changed the type of president we wanted, and he changed how we reacted to the ones we did not want. When he betrayed the public’s trust with his use of executive power to cover up a crime, he opened up the presidency to a level of scrutiny never witnessed before. The public no longer esteemed the office or held it in near-mythological high regard. The president became fair game for more extensive criticism from Congress, the media, and the American people.

Before 1974, marches on Washington – like the 1932 Bonus Army march and the great civil rights march – addressed either Congress or the American public. When 10,000 Americans marched in Washington on April 27, 1974, they did so in protest of the president himself for his gross misconduct in office. On January 21, 2017, 3.3 million people in America alone marched to protest Donald Trump, his personality, his policies, his past sexual misconduct, and his presidency. The Women’s March on Washington is part of a newer tradition of protests, one in which participants feel comfortable directly calling out the president and asking him to answer for his actions.

So thanks, Richard Nixon, for inspiring in Americans the righteous anger needed to publicly gather and demonstrate against our new president.