Bernie Sanders has come a long way from where he started three years ago. The thousands of supporters who attended his rally in Downtown Los Angeles on Saturday are proof of the movement he has built.

Sanders was in LA as the second stop on a weekend tour across California that also took him to San Diego and San Francisco. The campaign blitz was Sanders' first time to the Golden State as a candidate for the Democrats' 2020 presidential nomination.

Since running for president back in 2016, Sanders has been catapulted from narrow recognition among progressives to icon status among mainstream liberals, and the main points from his 2016 platform — raising the federal minimum wage, creating universal healthcare, protecting the environment, reforming the criminal justice and immigration systems, and making public universities free — have become litmus test issues for his Democratic rivals.

After announcing his bid for president in February, Sanders raised nearly $6 million in just 24 hours — setting records and surpassing the fundraising efforts of every other Democratic presidential candidate to that date. (Beto O'Rourke recently outdid Sanders after announcing his own bid for the White House: $6.1 million in his first 24 hours.)

Sanders' ideology, which only three years ago was commonly labeled as radical, has now been embraced by a wide swath of the Democrats seeking their party's presidential nomination.

"The ideas that we talked about were considered by establishment politicians and mainstream media as being too radical, too extreme," Sanders said to cheering supporters on Saturday. "A funny thing has happened over the last couple of years: turns out that justice is not too radical an idea for the American people."

Sanders' rise in popularity is in large part due to his support among millennial progressives. According to Tufts University, Sanders collected more votes in 2016 from young people than Hillary Clinton and Donald Trump combined, and in early Iowa polls, Sanders is only 2 points behind front-runner Joe Biden, who has yet to announce his candidacy. Indeed, Sanders' popularity has grown by 6 points since he first visited Iowa in December.

"In 2016, Bernie Sanders platform was widely seen as very leftist, not able to be accomplished, but now a wide majority have embraced his platform," Thomas Martin, a USC sophomore who attended Sanders' Saturday rally, said.

USC students attend the rally to support Bernie Sanders. (Annenberg Media / Morgan Stephens)
USC students attend the rally to support Bernie Sanders. (Annenberg Media / Morgan Stephens)

He was brandishing a "Trojans for Bernie" sign.

When Sanders challenged Hillary Clinton for the Democratic nomination in 2016, he presented himself as a direct counterpoint to her left-of-center platform. Sanders eventually lost to Clinton, but not before transforming the ideology and mechanics of the Democratic party.

Sanders supporter Erika Garcia wears a shirt that says “Hindsight is 2020.” (Annenberg Media / Morgan Stephens)
Sanders supporter Erika Garcia wears a shirt that says “Hindsight is 2020.” (Annenberg Media / Morgan Stephens)

His 2016 candidacy exposed structural bias in the Democratic primary process and catalyzed internal party reform, particularly after former Democratic National Committee Chair Debbie Wasserman Schultz's emails were leaked and the party was proved to have favored Clinton and taken steps to undermine Sanders.

Sanders has since become the anti-establishment leader on the left, and, similar to President Donald Trump's rightward transformation of the Republican Party, Sanders has pushed Democrats leftward to a socialist vernacular and more progressive politics.

He is more than willing to be a direct check on the Trump administration's policies and personally criticize the president, from condemning his unwillingness to recognize political corruption in Saudi Arabia to labeling him an authoritarian demagogue.

"Donald Trump is an embarrassment for us and much of the world," Sanders said on Saturday, later referring to him as "the most dangerous president in American history.

Sanders' following also comes from his decision to completely reject donations from Super PACS and corporations. In 2016, he commonly bragged that the average amount of a donation to his campaign was $27. Other Democratic candidates like Sen. Elizabeth Warren, Sen. Kirsten Gillibrand, and former Rep. Beto O'Rourke have now made similar pledges to reject PAC money.

Indeed, many other Bernie-isms from 2016 are being proposed by many of his Democratic rivals. Sens. Kamala Harris, Elizabeth Warren and Corey Booker co-sponsored legislation to create a public healthcare option, and polling consistently finds that a majority of Americans favor the government doing more to provide healthcare for its citizens. Sanders has been insisting for decades that healthcare is a human right.

He has also brought a deeper understanding of democratic socialism to the fore. The famously independent senator defined his political ideology in a televised debate in 2015.

"It is immoral and wrong that the top one-tenth of one percent own almost as much wealth as the bottom 90 percent," he said.

A Bernie Sanders supporter attends the rally in Los Angeles. (Annenberg Media / Morgan Stephens)
A Bernie Sanders supporter attends the rally in Los Angeles. (Annenberg Media / Morgan Stephens)

What made him an outlier in 2016 has now expanded in Congress and beyond. Two new House members, Alexandria Ocasio-Cortez and Rashida Tlaib, who identify as democratic socialists were elected in 2018, and a number of democratic socialist candidates won in state and municipal elections.

Ocasio-Cortez, Tlaib and Ilhan Omar have made names for themselves as staunchly progressive lawmakers, and their election makes House Speaker Nancy Pelosi look increasingly centrist.

Through it all, Sanders' insistence in a progressive agenda remains the same, and now it's clear that where Sanders leads, others follow.