Issa chaired the House Oversight and Government Reform Committee from January 2011 to January 2015; he's now in a close race against Doug Applegate, a retired Marine colonel. Although Issa opened investigations of matters including the Internal Revenue Service and the attack on a US compound in Benghazi, Libya, he recently sent a mailer with a photo of Obama signing legislation that provides victims of sexual assault new federal legal protections. The brochure says Issa was "pleased" that the President signed the law, which he co-sponsored.
Obama told more than 60 donors that "Issa's primary contribution to the United States Congress has been to obstruct and to waste taxpayer dollars on trumped-up investigations that have led nowhere. And this is now a guy who, because poll numbers are bad, has sent out brochures with my picture on them touting his cooperation on issues with me".
He added: "Now, that is the definition of chutzpah. Here's a guy who called my administration perhaps the most corrupt in history - despite the fact that actually we have not had a major scandal in my administration - that, when Trump was suggesting that I wasn't even born here, said, well, I don't know, was not sure. We can pull up the quotes."
San Diego was Obama's second stop yesterday. Earlier, he campaigned for Clinton and Democratic Senate candidate Catherine Cortez Masto in Las Vegas.
Trump is starting the week with a focus on two critical states in the Southeast: Florida and North Carolina. In a sign of the intense battle over Florida - a state in which both the GOP standard-bearer and Democratic vice presidential nominee Tim Kaine will be campaigning - Trump and Kaine's planes were parked on the same Miami tarmac.
National polls
RCP poll averages
Hillary Clinton 48 + 6.1
Donald Trump 41.9
Favourability ratings
Clinton +15.8
Betting odds
Clinton 84, Trump 16
Battleground states
Strong Clinton:
Virginia + 8
New Hampshire +8
Colorado +7.2
Wisconsin +7
Pennsylvania +6.2
Michigan +5.2
Maine +5.2
Leaning Clinton:
Minnesota +4.3
Nevada +4.2
Florida +3.8
North Carolina +2.1
Toss-up Clinton
Arizona +1.3
Toss-up Trump:
Ohio +0.6
Leaning Trump:
Iowa +3.7
Georgia +4
Texas +4.8
Strong Trump:
Missouri +6.7
Trump arrived in Boynton Beach, Florida, to convene a roundtable discussion with farmers at Bedner's Farm Fresh Market. He also will hold similar events with first responders in St Augustine and veterans in Tampa, as well as rallies in both cities.
Before leaving Miami, the New York real estate magnate did a radio interview with WBT Radio host Bo Thompson, making his case to listeners in Charlotte.
He accused the media of engaging in "a pile-on, the likes of which nobody's ever seen".
Trump said: "Because I'm going to protect the people, and the media are the exact opposite and they, you know, represent the opposite". He added he has a development near Charlotte that has been a "tremendous success" and would contribute to him winning the state. "So I understand North Carolina very well."
In another effort to shake up the race's dynamics, Trump campaign manager Kellyanne Conway suggested in an interview with New York radio host John Catsimatidis that the GOP nominee would be open to participating in a fourth presidential debate "for a very simple reason: Unless you're a moneyed donor, you're not going to have much access to Hillary Clinton out on the stump now.
"And so to give people a free opportunity to see them side by side and have them really mix it up on the issues, to me, is the purest form of democracy," she said, adding that Trump will be travelling to "three or four states a day" to "bring his case directly to the people."
Clinton, who has been bragging on the campaign trail that she beat Trump in all three debates, is highly unlikely to entertain that option.
