Republican presidential candidate Donald Trump speaks during a campaign rally, Tuesday, Oct. 18, 2016, in Colorado Springs, Colo. (AP Photo/ Evan Vucci)
Republican presidential candidate Donald Trump speaks during a campaign rally, Tuesday, Oct. 18, 2016, in Colorado Springs, Colo. (AP Photo/ Evan Vucci) Credit: Evan Vucci

Washington — President Obama all but invited Donald Trump on Tuesday to jump into a fight with him, baiting the Republican nominee as he faces an overwhelming disadvantage in the polls just three weeks before Election Day.

Speaking to reporters at the White House, Obama mocked Trump for complaining, while the race is still afoot, that the vote-counting system may be “rigged.”

“If you start whining before the game’s even over, if whenever things are going badly for you and you lose, you start blaming somebody else, then you don’t have what it takes to be in this job,” Obama said, his voice cracking with amusement.

“I’d invite Mr. Trump to stop whining and go try to make his case to get votes,” he said.

Though taking on the popular sitting president would be an unconventional strategy at this point, Trump has proved that he is susceptible to provocation, and Obama seemed to be aiming straight for that vulnerability.

Trump, whose disdain for Obama dates back to his amplification of the so-called birther movement that tried to delegitimize Obama’s presidency, publicly held his fire, referring to Obama only generally at a rally.

But a more significant rejoinder appeared to be in the works; he plans to invite Obama’s estranged half-brother as his guest to tonight’s final presidential debate, a campaign aide said.

Malik Obama, a few years older than the president, is the son of Obama’s father and a different wife. He has met the president a few times, but the two are not close. He has told reporters in recent weeks that he supports Trump for president.

For Trump, the prolonged silence was a departure. He has repeatedly responded to criticism by firing in anger, fueling Hillary Clinton’s argument that he lacks the temperament to serve as president.

Trump feuded with Fox News anchor Megyn Kelly after she questioned him harshly during the first GOP primary debate last year, and he spent days during the summer complaining after the parents of an Army captain killed in Iraq criticized him.

After the first presidential debate, as Trump attacked a former Miss Universe whom he had publicly shamed for gaining weight, polls show supporters began steadily abandoning him.

Obama’s direct jab at Trump was the culmination of Democratic efforts to frame the election not just as a choice between party philosophies but as a crucial moment in American democracy. The delivery of their message has grown increasingly dire as Trump levels charges of a vast conspiracy to rob him of electoral victory.