Waving a clipboard and calling for more citizen activism, former president Barack Obama returned to the campaign trail Saturday, reprising his role as the Democratic Party’s biggest star at a California rally for seven U.S. House candidates.

The event came nearly 20 months after Obama left the White House and committed himself to withdrawing from the daily political debate in the tradition of presidents past. In recent days, however, he has made clear that he can no longer remain restrained.

“The only way we reverse that cycle of anger and division is when each of us as citizens step up and say we are going to take it upon ourselves to do things differently,” he told a crowd of 900 at the Anaheim Convention Center, his shirt sleeves rolled up his arms. “We’re going to fight for the things that we believe in.”

Unlike the blistering speech he delivered Friday in Illinois, where he compared President Trump to a demagogue and described the current moment as a time of “political darkness,” Obama offered no pointed critiques of his successor — or mention him by name. Instead Obama struck a light note, focused on the biographies of California candidates he was there to help, calling out his love for the crowd three times, and even recounting his childhood visits to nearby Disneyland.

His central message, which he hit repeatedly, was that Americans needed to become more involved in electoral politics. He praised the outpouring of Democratic energy in recent special elections, and called for more.

“During these times of uncertainty it is always tempting for politicians for their own gain and people in power to see if they can divide people, scapegoat folks, turn them on each other,” he said. “The biggest threat to our democracy, as I said yesterday, is not one individual. It is not one super PAC billionaire. It’s apathy.”

Former president Barack Obama speaks during a Democratic Congressional Campaign Committee rally at the Anaheim Convention Center on Saturday. (Barbara Davidson/Getty Images)

Obama stood on stage with six of the seven California Democrats running in Republican-held districts that Hillary Clinton won in the 2016 election. The state is a central battleground in the Democratic effort to flip 23 Republican seats and retake control of the U.S. House.

Mike Levin, one of the congressional candidates Obama praised in his talk, said the visit had been a boon for his volunteers and supporters. “This will energize them,” said Levin, who is running in a district that includes parts of Orange and San Diego counties.

Obama will attend a second rally Thursday in Ohio for Democratic gubernatorial candidate, Richard Cordray, a former Obama appointee. These are Obama’s first public campaign events since he attended rallies for Virginia Gov. Ralph Northam and New Jersey Gov. Phil Murphy in 2017. He has also attended several fundraisers for Democratic efforts, recorded a robo-call for Alabama Sen. Doug Jones and this summer he released his first round of 81 federal and state-level endorsements.

President Trump has so far greeted Obama’s return to politics with a mixture of sarcasm and disdain. Trump initially dismissed the Friday speech as boring. “If that doesn’t get you out to vote for the midterms, nothing will,” he said sarcastically on Friday, while visiting Sioux Falls, S.D.

Trump later retweeted several posts contesting parts of what Obama had said. One forwarded message from former Fox News anchor Eric Bolling argued that Obama was trying to take credit for Trump’s economic success. The tweet derisively summarized the successes of the Obama presidency as simply “Slick Speaking” and “School Shootings.”

Trump also retweeted a post from Richard Grenell, the U.S. Ambassador to Germany, who noted the Trump administration had recently deported a former Nazi. Obama had criticized Trump for failing to sufficiently condemn Nazis who had marched in Charlottesville, asking, “How hard can that be, saying Nazis are bad?”

The event Saturday in Anaheim was scripted to appeal broadly beyond the activist base, who filled the crowd of hundreds. Two of the speakers before Obama identified themselves as current or former Republicans. Others gave testimonials about the need for protections provided by the Affordable Care Act, also known as Obamacare.

“The big blue wave starts right here in California,” said Eric C. Bauman, the chair of the state Democratic Party, before offering a fresh twist on Trump’s slogan. “This election is about fixing America again.”

Irvine resident Bob Nicoll, a training manager for a computer game company, was one of the attendees who received a ticket to the event through the Democratic Congressional Campaign Committee.

“We’ve had enough,” he said before Obama spoke. “Truth matters. We all feel mobilized.”

A group of about six Trump supporters gathered outside the hall where Obama spoke, including one who only would speak with a Post reporter through a bullhorn, shouting that the reporter was “scum.”

After the speech, protester Arthur Schaper said he and other Trump backers are “fed up with lies being said about the president.” A Democratic “blue wave” in November “ain’t going to happen,” he said.

Scherer reported from Washington. Josh Dawsey contributed to this report from Sioux Falls, S.D.