Lately, though, he's had another target in his sights: Republicans.
On his last two foreign swings, Obama has offered blistering criticism about the slate of candidates who are vying to replace him on the GOP side, lambasting their policy proposals and implying they lack the gravitas to do his job.
His remarks wouldn't sound out of place during a press conference in the White House briefing room or at a speech to a room of Democratic fundraisers. But it's a new phenomenon for Obama -- and rare for U.S. presidents generally -- to use such pointed language about political rivals on the world stage.
Some of those rivals aren't pleased.
"I would encourage you, Mr. President, if you want to insult me, come back and insult me to my face," dared U.S. Sen. Ted Cruz of Texas Wednesday, after Obama went after his proposals for Syrian refugees while traveling in the Philippines to attend a regional economic summit.
Obama's aides say the President is simply calling out Republican language that deserves scrutiny -- including what he says are "offensive" intimations about refugees from Syria. The decision to respond while abroad, they say, is merely a facet of his schedule.
But it is a practice Obama has only engaged in more recently, and it follows a new, unguarded manner for Obama. Unrestrained by another election bid and the possibility that his words could adversely affect his political standing, Obama has taken to blunt assessments of his rivals' policies whenever they arise. Unconcerned about allegations he's abusing his bully pulpit abroad, Obama has used the foreign trips to underscore his global stature -- and make a tacit comparison to what he sees as his critics' lesser positions.
The latest example came Wednesday, when Obama -- asked about some Republicans' calls to stop Syrian migration into the United States -- lit into the field of candidates, who have almost uniformly called for curbs on the refugee flow.
"They've been playing on fear in order to try to score political points or to advance their campaigns," he said, standing alongside Philippines President Benigno Aquino, who is hosting a yearly summit of Pacific nation leaders in Manila.
The harsh comments from Obama come as Republicans are increasing their attacks on him after ISIS's devastating attacks in Paris, which left 129 people dead.
The President maintained in a press conference Monday at the start of his trip to Asia that his current strategy for combating the terror group is working, but he was criticized on both sides of the aisle for defensiveness and testiness during his remarks. And his willingness to engage in partisan politics while on foreign soil is another point the GOP is using in blasting his approach.
Cruz suggested the two men hold a debate on the issue, criticizing the venue that Obama has chosen: "We can do it anywhere you want. I'd prefer it in the United States and not overseas where you're making the insults. It's easy to toss a cheap insult when no one can respond."
Though Obama didn't mention Cruz by name, it was clear that he along with former Florida Gov. Jeb Bush was a target of the President's remarks condemning candidates who have recommended that the U.S. accept only Syrian Christians fleeing the civil war in their country. Both Republicans have suggested allowing only Christians from Syria into the U.S.
"When you start seeing individuals in positions of responsibility, suggesting that Christians are more worthy of protection than Muslims are in a war-torn land, that feeds the ISIL narrative," he said, using another term for ISIS. "It's counterproductive, and it needs to stop."
Two days earlier Obama issued another barbed challenge to another Republican candidate, Dr. Ben Carson, who has suggested his foreign policy advisers had better intelligence about the situation in Syria than the White House.
"If they think that somehow their advisors are better than the Chairman of my Joint Chiefs of Staff and the folks who are actually on the ground, I want to meet them," taunted a visibly irritated Obama. He was speaking at the conclusion of the Group of 20 meetings held on the Turkish coast.
But the President hasn't always been so willing to wade into domestic politics while speaking at an international podium. When he was running for re-election in 2011 and 2012, he avoided sharp criticism of his would-be Republican challengers even when questioned about the race.
At a November 2011 G20 meeting in the South of France -- the same time in the electoral cycle as this year's meeting in Turkey -- Obama said the upcoming election battle wasn't a priority.
"I have to tell you the least of my concerns at the moment is the politics of a year from now," he said when asked about his re-election prospects in the face of a weak economic report.
Even at the next year's summit, held in Mexico five months before Election Day, Obama insisted that domestic politics weren't on his mind.
"I think it's fair to say that any -- all these issues, economic issues, will potentially have some impact on the election," he said, again responding to questions about the economy. "But that's not my biggest concern right now."
Even given a chance to respond to his then-rival Mitt Romney, whose top adviser had written an article critical of the Obama in a German newspaper, the President demurred.
"I would point out that we have one President at a time and one administration at a time, and I think traditionally the notion has been that America's political differences end at the water's edge," he said.
In his final term in office, however, Obama has dropped whatever resistance he had previously to lambasting his potential replacements.
Asked during a July trip to Africa about comments made by former Arkansas Gov. Mike Huckabee -- in which the Republican White House hopeful claimed Obama's Iran nuclear deal amounted to marching Israel to "the door of the oven," a reference to the Holocaust -- Obama lit into the field at large.
"The particular comments of Mr. Huckabee are, I think, part of just a general pattern that we've seen that is -- would be considered ridiculous if it weren't so sad," he said during a news conference with Ethiopian Prime Minister Hailemariam Desalegn.
He went on to decry "a culture that is not conducive to good policy or good politics."
"The American people deserve better," he said. "Certainly, presidential debates deserve better. In 18 months, I'm turning over the keys -- I want to make sure I'm turning over the keys to somebody who is serious about the serious problems the country faces and the world faces."