But even before a well-heeled crowd of avowed Democrats, Obama didn't take the chance to hammer Clinton's Republican rival Donald Trump.
"Frankly I'm tired of talking about her opponent," Obama said at the event. "I don't have to make the case against her opponent because every time he talks, he makes the case against his own candidacy."
The fundraiser, held in the same forested town on Martha's Vineyard where Obama and his family are renting a secluded compound, brought in hundreds of thousands of dollars for Clinton's campaign.
Obama delivered remarks to 60 donors, who each paid between $10,000 and $33,400 to attend, and answered some of their questions. It was his first public event since beginning his vacation here a week ago.
In that span, polls have indicated Clinton with a decisive edge in many battleground states. But Obama warned against complacency ahead of a busy fall campaign season.
"If we are not running scared until the day after the election, we are going to be making a grave mistake," he said.
He talked up Clinton's national security credentials, saying that "until you sit at that desk and you're making life-and-death decisions, and you're deploying young men and women to war, or you're having to avert a crisis that could affect millions or in some cases billions of lives, you don't know how you're going to respond."
"I will tell you that I have as good a guess when it comes to how Hillary would respond as I would with anybody because I've seen her under really tough pressure situations," he said.
"She's not always the flashiest; she's not always the person who's going to give you the big stem-winder," Obama said. "But she is the person who's going to do the work."
Before he departed for his two-week stay on Martha's Vineyard, Obama declared Trump unfit for the presidency. He's expected to spend much of the fall stumping for Clinton.
Monday's event is hosted by Hank Goldberg, a real estate investor, and his wife Carol Brown Goldberg, a mixed-media artist. Land records show the couple actually own two homes in Chilmark on abutting lots. Each is valued at more than $4 million.
The Goldbergs were originally slated to host a fundraiser with Obama at their enormous condo in Chevy Chase, Maryland, in May. But the White House determined the time it would take to drive there from Washington, even in a motorcade, would occupy too much of the President's day. Instead they tried switching the venue to the Jefferson Hotel (a frequent fundraising spot for Obama only two blocks from the White House). But the Goldbergs weren't interested.
The details of the deliberations were revealed in hacked Democratic National Committee emails that were posted by Wikileaks, including some salty language from DNC staffers miffed at losing out on what they expected to be a high-yield event.
"They really won't come down 20 minutes?" one staffer wrote. "Thats f**k**g stupid."
"He really won't go up 20 minutes for $350k?" another staffer responded. "THAT'S f**k**g stupid."
"Or he is the president of the united states with a pretty big day job," was the terse reply.