If you want to glimpse the future of the Democratic Party, look at Riverside County, where the number of registered Democrats surged past the number of Republicans. In an historic shift, a county that was solidly conservative “red” for decades seemed to turn Democratic “blue” overnight.

This unprecedented change is the result of a concerted effort to register and engage as many California voters as possible in 2016. It was made possible by the hard work by community groups, voter engagement organizations, labor unions and the California Democratic Party.

They are building a statewide infrastructure to reach the seven million eligible California voters who have not registered, and they deserve high praise for re-energizing our democracy.

Yet none of this would be possible without one unwitting ally: Donald Trump.

His hate-filled presidential campaign has awakened Californians to the hazards of apathy at the polls. Record numbers of Californians are answering the call and registering. Despite the nonpartisan nature of most voter registration drives, Democratic registration is surging, thanks to the Republican nominee’s divisive message.

Earlier this year, I grew very concerned about Trump’s vicious rhetoric and decided to act. One approach stood out as the smartest and most effective: a massive voter registration and engagement campaign.

Just as the “Prop. 187 Effect” sparked by Pete Wilson’s attacks on Latinos in 1994 started the California Republican Party’s slide to irrelevance, we anticipated a “Trump Effect” that could galvanize a new generation of voters.

In February, I announced plans for an unprecedented voter registration effort. Our goal: to awaken California’s sleeping progressive giant — the 7 million eligible Californians who don’t vote.

Since then, my organization, NextGen California, has partnered with more than 40 grass roots voter registration groups in 30 counties around the state. We’ve deployed resources and made grants to expand voter registration efforts from Eureka to San Diego. These efforts have helped make 2016 a banner year for voter registration in California.

California now has the second-highest number of registered voters in history and the highest number of registered Democrats ever. Yet we are nowhere near done.

In the next month, we’ll set an even more ambitious goal. We want to make 2016 the biggest year in history for voter registration and participation. That means reaching potential voters through radio, television and print. It means knocking on doors, blanketing public places and engaging people on social media.

We believe democracy is stronger when more people vote. We believe our diversity is our strength, and wider representation yields superior results. Contrast this with the approach taken in some parts of the country, where retrograde laws to restrict voter participation are key parts of the strategy. This anti-democratic approach goes hand-in-hand with the nomination of a candidate who offends large and growing portions of the electorate.

For California’s newly registered voters and for young members of the millennial generation, this election will be a generation-defining event. They will choose the future they want to see, and the choice is clear. Riverside County offers a glimpse of the California to come — a state in which even traditionally Republican strongholds shift to favor Democrats.

As Trump continues his parade of attacks on huge swaths of the electorate, we’re gearing up. We want to make 2016 a turning point for our democracy.

Can this be the year when the trend of record-low voter turnouts yields to record-high voter engagement?

Trump has seriously harmed the national political discourse. But if there’s a silver lining, it’s the fact that in California, we have leveraged this negativity to yield positive and lasting results for our democracy.

Tom Steyer, an environmentalist and former hedge fund manager, is president of NextGen California. He wrote this for The Mercury News.