He criticized Republicans for taking credit for an economic recovery that began under his presidency, and for enabling Trump to pressure the Federal Bureau of Investigation and the Department of Justice to punish his political enemies.
The event officially ended Obama's absence from the campaign trail, a months-long void that has angered some Democrats who believe he is not engaging in a political fight where he could be helpful.
"Our antibodies kick in and people of good will from across the political spectrum call out the bigots and the fear mongers and work to compromise and get things done and promote the better angels of our nation".
"Obama has Trump Derangement Syndrome".
"What bothers me is that if what was written was true, then there is a cabal in the White House that's working against the president", said Paterson, who also served as the New York Democratic Party's chairman. Obama didn't mention President Donald Trump by name during a 20-minute speech in the key Southern California battleground of Orange County.
"I'm sorry, I watched it, but I fell asleep", he said at a campaign appearance in Fargo, North Dakota.
He told the audience they were coming of age at one of those moments.
Big rigs abandoned as wildfire scorches California freeway
The Delta Fire was burning on both sides of Interstate 5, which has made it more hard to control the flames, Underhill said. This is partially because three fires merged into one fire, but also because the fire is extremely active at the moment.
With the adulation lavished on Obama's speech in IL on Friday, where he repeatedly took shots at Trump, saying Trump's Twitter feed is nothing more than an "electronic versions of bread and circuses", insiders worry Obama's return could throw Trump off his game.
"He was trying to take credit for this incredible thing that's happening to our country", Trump said, accusing Obama of overseeing the "weakest recovery in the history of our country" since the Great Depression.
The speech was a preview of the argument that Mr Obama is likely to make until the United States midterm elections in November. "And if you thought elections don't matter, I hope these last two years have corrected the impression". He will spend this Saturday in California stumping for seven congressional candidates at a Democratic Congressional Campaign Committee event and will head to OH next week to campaign for gubernatorial candidate Richard Cordray.
"These are some of the men and women, many of them who never imagined running for office", the former president said of the California candidates.
"I want to reach out to some Republicans, who kind of hearken back to the values of a guy named Abraham Lincoln, the first Republican president".
"They are not doing us a service by actively promoting 90 percent of the insane stuff that is coming out of this White House and then saying, 'Don't worry. It's radical. It's a vision that says our protection of our power is all that matters", Obama said. "All that matters ... is getting out there and voting".
Obama shared the billing with seven Democratic candidates in competitive U.S. House districts across California.
This content was republished with permission from CNN.