There was no better proof of how we have failed as voters than the scene at last week’s NAACP convention, where former President Bill Clinton presented me with the group’s award for outstanding achievement.

As I told 2,000 attendees in San Antonio, if we had all done our job and voted in 2016, it would have been President Hillary Clinton making the presentation.

It got a laugh, but it is the bitter truth.

President Trump is where he is today because of our collective failure to militantly and consistently participate in the political process. After our tremendous victory in electing Barack Obama twice, we had to know that we were in for a fight in 2016.

Hillary Clinton lost the presidency not only because of the anti-Obama backlash, but also because we Democrats went slack, then did what we so often do — we fought among ourselves.

Granted, Russia helped Trump. It may even have been the difference when you look at how close the vote was in states like Wisconsin, Michigan, Pennsylvania and Florida that put Trump over the top.

But every Berniecrat who couldn’t get over it, every Democrat who saw the election as the choice of two evils and sat it out, every unengaged citizen who didn’t engage — they contributed to our arrival at the point where everything we’ve gained since Brown vs. Board of Education is at risk.

And that’s why it was Bill Clinton draping the 103rd Spingarn Medal around my neck in San Antonio.

I was truly humbled to join the company of Martin Luther King Jr., Thurgood Marshall, Rosa Parks, Harry Belafonte and all the others who have been honored with the NAACP’s award.

And as I said from the stage, “No individual achieves such a high honor alone. If you ever see a turtle sitting on a fence, you’d know that turtle didn’t get there by himself.”

At the same time, however, I am deeply worried that the achievements of all the men and women who came before me are in danger of being eroded away. Not just by Trump and his ilk, but by ourselves.

It will get worse unless we exercise that right so many people have fought for — our right to vote.

Mystery endorsement: The California Democratic Party’s executive board appears to be on a suicide mission.

Endorsing Kevin de León in his bid to unseat fellow Democrat Sen. Dianne Feinstein is a total disconnect from what party members did in the June primary, when they overwhelmingly backed Feinstein. She even beat him in his state Senate district in Los Angeles.

Chalk it up to a couple of things. For starters, the Berniecrats turned out in force for the delegate elections last year, and they see Feinstein as being weak on Trump.

Second, Feinstein’s operation failed to connect with delegates, while de León was on the phone with them nonstop.

The result, however, will probably be less money for the party as it tries to win the GOP-held House seats it’s targeted in California — national donors who like Feinstein aren’t about to give to a state party that puts de León on its slate cards.

It may also hurt Sen. Kamala Harris if she runs for president in 2020 and she’s joined in the public’s mind with a state party that’s fallen off the left edge of the Earth.

It’s not like the endorsement is actually going to help de León win in November. But it does let him save face, and it may boost him in what I think is his true ambition: to run for mayor of Los Angeles down the line.

A pro: My friend and sometimes driver Gary Radnich is leaving TV at the end of August after 34 years. Having watched Gary all these years and worked with him for two years on commentary after 49ers games for Comcast, I can say there is no better sportscaster in America.

And he doesn’t need a script! My kind of guy.

Movie time: “Skyscraper”: Dwayne Johnson, a.k.a. the Rock, does it again with an action-packed drama — this time on one leg and on a burning building in China that’s three times the height of Salesforce Tower.

“Skyscraper” will make more money than any of the better-scripted, better-filmed and better-acted movies this summer because it’s pure entertainment. And believe it or not, people still go to the movies to have fun.

The city that knows how: San Antonio has it together. No trash, no panhandlers, no tents, and seemingly a one-to-one ratio of citizens to electric scooters.

No trip to San Antonio would be complete without a visit to the Alamo. It’s an impressive place, bullet holes and all.

I stopped by the gift shop where they have Davy Crockett “coonskin caps” for sale.

“Might think about changing the name of those hats,” I joked to the clerk.

Want to sound off? Email: wbrown@sfchronicle.com