Former US president Barack Obama speaks during his midterm campaign in Orange County in support of California congressional candidates in Anaheim, California. AP
Former US president Barack Obama says the November midterm elections will give Americans “a chance to restore some sanity in our politics”, taking another swipe at his successor as he raises his profile campaigning for fellow Democrats to regain control of the House.

Obama didn’t mention President Donald Trump by name during a speech on Saturday in the key Southern California battleground of Orange County but the allusions were clear.

“We’re in a challenging moment because, when you look at the arc of American history, there’s always been a push and pull between those who want to go forward and those who want to look back, between those who want to divide and those are seeking to bring people together, between those who promote the politics of hope and those who exploit the politics of fear.”

His appearance - a day after a strongly-worded critique of Trump at the University of Illinois - touched on themes of retirement security, climate change and education.

“If we don’t step up, things can get worse,” Obama told an audience at the Anaheim Convention Centre. “In two months, we have the chance to restore some sanity to our politics. We have the chance to flip the House of Representatives and make sure there are real checks and balances in Washington.”

Obama gave shout-outs to seven Democratic candidates in competitive House districts across California that are considered crucial to the party’s efforts to oust Republicans from control. Four of those districts are at least partly in Orange County, a formerly reliable GOP bastion that went for Hillary Clinton in the 2016 presidential election.

“We’re going to put on our marching shoes, we’re going to start knocking on some doors, we’re going to start making some calls,” he said to cheers.

Clinton trounced Trump by more than 4 million votes in California in 2016 and carried Orange County by 9 percentage points. A surge in immigrants has transformed California and its voting patterns. The number of Hispanics, blacks and Asians combined has outnumbered whites in the state since 1998. Meanwhile, new voters, largely Latinos and Asians, lean Democratic.

In Orange County, Republicans held a 13-point edge in voter registration 10 years ago but that has shrunk to 3 points while independents have climbed to 25%.

Obama is expected to deliver a similar message in Cleveland on Thursday, when he campaigns on behalf of Richard Cordray, the Democratic nominee for Ohio governor, and other Democrats. AP